I think the Emperor knew that Chaos would make a play. What he didn't know was the timing and what form it would take. The Emperor probably thought he could finish the webway project before anything could stop it.

It’s pretty clear that Dorn was brought to turn Terra into a fortress in defense of the webway gate. However, I feel that the thousand sons should have been brought along side the imperial fists. Include Magnus in the webway project since he was supposed to be the one to run it, and charge dorn with protecting it from external attack.

Imagine Perterabo fortifying Luna or Saturn's ring while Dorn fortified Terra. Big E using their rivalry to a constructive end, while giving the Lord of Iron a chance to show what he could do

Dorn and Perturabo were meant to be complimentary counterparts in their respective fortification and siegecraft ability. Arguably, every Primarch had a counterpart which ironically sewed division.

Malcador literally had said on multiple occasions in the most recent siege books that plans were set in place for the most likely futures. He also said that he and the big E both knew that he could use the golden throne some time ago. He also said that the emperor ascending was always as option. When he was watching kila, he was talking about faith in emperor denying chaos and powering the emperor. Dark imperium novels explicitly stated that humanity greatest weapon is faith. It can bend the warp to its will but also the most dangerous weapon.

As it drew closer and closer, the emperor could see it ever more clearly. He knew a heresy and civil war would happen. He didn't know exactly how

The Emperor did know, though. This was mentioned across a few books. In Emperor of Mankind her said he knew the future but not the minute details. They knew that the Warmaster would turn. The demons called Horus the sacrificial son for this reason. In Outcast or Nemisis, they went to warn of Horus betrayal, but Malcador already knew. And in Alpha Legion novel they said if Mankind outright won it would be bad. If chaos won then the universe would eat itself. An eternal war gave them extra time, so he took 1 legion instead of many

It's worth remembering as well that if it wasn't for Magnus then the Custodes, Sisters of Silence and the Emperor himself could have been a lot more involved with the Heresy and tipped the balance in favour of the loyalists early on.

That game of Regecide Big E had with Malcador showed they had a good understanding of what was going to happen.

The average Farseer can see pretty well into the future. It'd be pretty unbelievable to think the emperor could not. I personally think he did foresee it, knowing that eventually it would lead to godhood; despite what he outwardly said he was against. It was the path to true victory.

I think you missed the primarch that represents the biggest hole in the idea that the Emperor knew that the heresy was coming. Magnus was the most powerful psyker and was being groomed to sit upon the golden throne in the Emperor's stead. The Emperor had also discovered, at the council of Nikea, that Magnus had been delving too deep into the warp. If Magnus had been on Terra, the Emperor could have taught and guided Magnus's experiments with the warp, while also keeping an eye on him. And then, if a rebellion broke out, Magnus could take the Emperor's place on the throne if it came to that.

The emperor didn’t plan the heresy, but he did plan for it. And my guess is that he chose Dorn to be his praetorian for the simple reason that he was the most incorruptible of all of the primarchs bar maybe Vulkan, and he picked Horus, because he knew that whoever he picked as Warmaster was guaranteed to fall, and Horus was the one who’s tactics would be easiest to predict whilst also annoying the rest of his sons the least. Unlike if he picked Angron, for example

There can be myriad reasons for such a deployment. The Emperor did not foresee the Heresy! Or if he did, he missed so many critical detail as to makes no different. The Sol system was becoming the capital of a Galactic Imperium, the traffic to it was colossal. It could well need a Praetorian to oversee it. If the Webway project suddenly needed a military element, having a Legion on hand makes sense. And then there is Mars. The twin Empire wasn't fully trustworthy, so having a Legion close by would help. Perhaps The Emperor foresaw a potential thread to the Sol system, and so made Dorn ready. As I said, many options.

The only legion that could've stopped the Istvan V massacre was also the only one that could protect Terra. Honestly the Emperor expected trouble, as in Master of Mankind he must had knew something was going to happen but didn't know the specifics, as such Dorn was a perfect pick, it is discreet since the rest of the crusade didn't need the imperial fist specifically and having other primarchs like Guilliman or the Lion could've arisen suspicions

He absolutely knew heresy would occur, the question was who would lead it and when. What I find interesting is how he decided to appoint Horus knowing whoever he chose would likely fall to Chaos.

Makes sense. You know what you do when you have won a great victory? You don’t keep pushing up, you consolidate and fortify your position

Corax definitely had Big E's absolute trust. The dude gave him the means, and technology that he himself used to craft the legions/primarchs after the DSM.

I would love to hear the theories of what difference it would of made if the Emperor had chosen Perturabo to be the Pretorian instead of, or aswell as Dorn.

Well, in The First Lord of the Imperium, Malcador mentions that he and the emperor knew/planned for the fall of half the primarchs. The only issue is, is that it happened sooner than they had expected due to the interference of the chaos gods.

The Emperor saw the Heresey as a potential future. This is similar to where he shows Magnus a futures where he turned his back on chaos and if Horus didn't fall. E can see far and wide but there are still things he can't control or account for.. if he acted on every possible future he couldn't get anything done.

I love it. Perfectly timed as well... was just singing the praise of Dorn & the VII Legiones Astartes.

He knew it was coming, the future is not easy to predict though, this was the best of possible futures, in other versions other primarchs turned while some remained loyal. I actually wouldn't mind a "What If" Heresy series.

I think he expected some kind of rebellion but couldn't be sure when or what form it'd take and was simultaneously handling things in the optimal way in balance of all options. His foresight not being perfect, he might have also been foreseeing other stuff that may have come to pass before or after a galactic civil war, such as needing the Ultramarines huge numbers on the eastern fringe where he expected first contact with the Tyranids would occur at some point, and just been off by millennia. Needing to continue to suppress Orks all over was an ever-present threat best handled by legion strength and Primarch leadership to smash. He knew Chaos could act anywhere so he needed his forces everywhere. Conquest is only complete if you can hold what you conquer and you can't do that if you close ranks and bring everyone home. By bringing Dorn home, it signalled a shift from outward conquest to holding what you had claimed at home and abroad.

I think it was to give Rogal Dorn the final instructions of exactly where to be and what to do with the Phallanx when the Emporer reaches godhood when Cypher kills his physical form. Its all going to plan. Before anyone says Dorns dead RIP..... Dorn lives! GW retconned the date of the Rynn's World Disaster to coincide with the end of the Indomitus Crusade. The book Rynn's World happens to give a fairly solid hint that Dorn is alive (Dorns actual blood returns from dust to blood inside a relic once a year on CFs home world.) I can't think of any other reason GW would retcon the date of the disaster if they weren't planning on Dorn returning and a IF, CF and BT etc etc story arch. (BTs have had lore continuation and so have Crimson Fists. The CFs Chapter Master met Guilliman and was ordered by the primarch himself to "Stand ready!" (what ever that means). We have also seen continuation in the lore of the phalanx and IFs..... As a Dorn fan I can't wait for 11th Edition. After seeing 10th Edition play out similarly to 2nd Edition (UM and Nids) so far I think 11th Ed will be Dorns time to shine and we will see BT's and Dark Eldar in the box set like we did in 3rd Edition.

Malcador has a conversation with Sigismund and Raldaron in Dorns primarch novel, he lays out some of the big reasons he chose Dorn.

I think that in all the EoM visions of the future and the possible versions of the Hersey. It was just as important that the rest of Loyal Legions stay out in the galaxy. As for why especially Guillemin and Ultramarines were kept in galaxy. This goes back to the EoM seeing versions of the Hersey. By keeping the Guillemin and Ultramarines away, Logar, Angron and their legion focused on them totally. At the same time boys in Blue need to be there find the Pharos and set up Imperious Secondus to bring the Lion and the Angel there during the Ruin Storm. Only later for both Dark Angels and Ultramarines to help the Angel and his legion reach Terra just before the siege, something Horus hadn't expected.

I agree that it was a response for the Emperor working on the web way. To keep an eye on real space while he was in the warp.

I agree that the 7th were brought back to Terra to build upon the webway project. Not only would the paths that humanity would use through it need to be pacified & fortified, but also a Legion would be beneficial in dealing with the Navigators & their cartels. Also, I think the Custodes would stay to guard the palace. The 10,000 only fought the war in the webway during the heresy because Dorn & the 7th were then needed to fortify the Sol system & Terra.

The emperor should have taken Magnus with him. If it was his plan to have Magnus sit on the throne, it would’ve been smarter to get the Thousand Sons involved sooner to try and foil any Chaos power play

Lets not forget that during the game with Malcador, it was asked to the Emperor if he knows whats coming why allow it. The Emperor foresaw all the possibilities and the one that came through made sure the Loyalist Primarchs were the ones we know, as if any of them turned Traitor instead the consequences would be much worse. It basically all this was because of a massive butterfly effect the Emperor knew and chose the lesser evil.

Here are my 2 cents on the emperor only bringing back one legion. It has been said over and over that the Emperor can see a bunch of outcomes and he tries his best to steer it in one direction/help move humanity where he wants it to go. So there could be another 5000+ scenarios that could have been far worse if he took more than one. It's almost like playing the lesser evils game. If he took 3 legions then if everything worked out fine, he would be in a much better position, but that also means if it still went wrong, he could be in a fair more terrible position. So he would try to pick the closest to the medium of what he wants. Where if it goes wrong, he has the best possible solution and chances of fixing it. I may have explained that badly, but basically like gambling. You could put 2 dollars down, and if you win, you aren't really richer, but if you lose, you aren't really poorer. He could bet all 500 dollars, which means if he wins he is easily richer, but if he loses then he lost it all. As for seeing the treachery, there is some validation that the Emperor needed to become godlike, what is more godlike than something you can't really see anymore, but can still create miracles? If he started the crusade with claiming to be a god, then that means the chaos gods could easily show their existence, or other searching for the other "gods" that have to be out there. So he gambled on removing religion, and he wanted to get the gateway up so he didn't need the religious route, but it failed. So now his power is growing, because humanity fair outweighs everything out there. If everyone believes in the god emperor, then he should be stronger than the chaos gods himself. So that's my thoughts on it. Did he know there could be a treachery? Yeah, but he tried to play his cards to the effect of the least impactful ways, which is why it took him thousands of years to slowly move in a direction instead of an overnight gamble. :)

I think if the Emperor brought more legions back to Terra it would have tipped off the Chaos gods that something was going on. That and there was still lots more of the galaxy yet to liberate. Plus when you have more than one Primarch in the mix, egos and suspicions start to undermine things. Chances are someone would have done something to mess things up before Magnus even got close.

At the time, i think the emperor knew something was going to go down, so only taking one with him makes sense. Dorn and the Imperial Fist's are security, they can take over while the Custodes do other things and no lapses would likely happen.

It's interesting to think though that Perturabo, who always craved his dad's approval, would probably have stayed loyal if he were called back to Terra.

I'm pretty sure by now that the best way to reconcile the vast, VAST differences between how the Emperor treated the various Primarchs is to say that he planned for some to go rogue... and that he had his favourites. It might even be the only way to reconcile it. It might have started with just a combination of "bad" writing and poor to no oversight from GW, but at this point, the only decent way to keep all of the current canon meetings the way they are AND to keep the Emperor from being an absolute idiot is to say he planned for a Heresy. He just didn't know exactly how it was going to go.

I like the explanation given by Baldermort, he wanted to see the joy on Rogals face when they got the news that the great crusade was completed Call me an old romantic but I like it

Of course he knew. Just a question of how much and how detailed. If I was to speculate. I'd say he knew damn near everything. And he probably knew what would happen if humanity "won" but the warp remained tainted and corrupt. A similar fate to the eldar or worse long term.

The emperor planned the heresy. It might have always been the backup plan(certainly the end result was) but apotheosis was always the end goal. Had Magnus not goofed the emperor would have been there to sort it out, there are a couple of things that meant he had to plan for it (scattering, finding them, losing 2) but the webway stuff is what lead to very few options.

The Emperor knew what was going to happen and what needed to happen, to hold back the tides of Chaos the Imperial palace would need to be *Fortified* and who better than Rogal Dorn!

Whenever I heard conversation around the Emperor and his foresight, I instantly think of his lesson of foresight to Ra Endomyion. He can see the objcetive in the distance but there are too many possibliltys between here and there to know exactly what is going to happen. So he safe guarded Terra with the best fortifying leigon he had and the most stubborn primarch.

I’m a strong believer that The Emperor not only foresaw the heresy, but quite honestly engineered it himself. The crusade was merely the Emperor’s observation time for which primarchs would be able to continue on after humanity was reunited fully. I think the true twist of the entire heresy will be that it was always the emperor’s plan, but chaos’ intervention is what changed the players for both sides

Defending terra like you said makes perfect sense! However, I feel like he knew a civil war would come eventually. I just think he thought he had more time, preferably after the webway project was done and there was no other forces to fight. Then some legions would get itchy trigger fingers and rebel. He just REALLy underestimated chaos, probably didn't think they could/would put aside their differences to fight him together in such a fashion. Once the Webway was taken then it would not have been a big deal getting the legions from distant locations and returning to Terra.

Answer is simple. YES.

I expect he could see the Heresy but not WHO would turn and as such made the choice to bring back the one he was sure he could trust and was a speclist at defence fortification. It could be the Heresy could change based on who he was to bring back and what ever steps he took could change who would turn and as such made the only safe choice he could see. The Emp might of also forseen the webway backfire and flood the place with Demons maybe not why it happens but that it MIGHT and so wish for fortification incase. He might of been able to forsee the Nids or maybe the Necrons? or even maybe the War of the beast.

Each if you kept the Heresy "simple" for each Primarch going rogue, that would too many things to prepare for and too many things you would have to "Lets see if that happens"

If the Emperor should have taken Magnus to defend Terra. Dorn is the obvious choice on the physical defense, Magnus is the obvious choice to defend against the warp. Magnus makes the most sense since he was also destine to sit on the throne.

I know I give ya a hard time about too many smurf videos 📹 lol 😆. But I am very happy to watch and hear this video of Rogal Dorn!!!

What if the Emperor saw the Dornian Heresy instead, and called Rogal Dorn back to Terra to try and prevent it...

The emperor knew he who was chosen as warmaster would betray the imperium but The emperor didn't know how deep the Chaos Corruption went.

I've always thought that the simple answer was always the most likely and reasonable. Pretty much every faction would want to hit Terra, it's the heart of the imperium and the impact of losing this one planet would be an even greater blow than losing any entire system, possibly even any sector. If you want to make an empire long lasting at makes sense to ensure its capital can't get smashed by any of the many enemies out there, especially when there's enemies as powerful as the various factions of 40k. Plus the crusade was going well and was led by his very capable sons who all were able to continue without requiring the emperor's supervision or assistance. And so far the focus had been on expansion and conquest. It makes sense once things were reaching this stage to start delegating more tasks to others so he can focus on things like consolidating and fortifying what they have already gained, and proceeding to the next stage of his plans.

Rho I love your theory about using Rogal to defend the webway. But i have to believe that the Emporer and Malcador both knew about the Heresy. There was a mention of the Emporer and Malcador playing a game where the primarchs were pieces and playing the game with different mixes to see what happened. I believe this was done to see who should be warmaster and the best to align with whom.

Malcador mentions in Dorn's Primarch novel that one of the main reasons he was made Praetorian was because Rogal obeys Big E's orders to the letter, exactly as said without question. That's one of the overarching themes of the book too, if any of you haven't read it I definitely recommend it.

I think it poignant to recall that the navigator houses would no doubt crippled the EoM if they had heard about the near completion of the first human corridor through the webway. I subscribe to this being the reason for secrecy.

The Heresy started just after Monarchia, when Lorgar started to look for a new truth. And Dorn was to fortify the webway so they could conquer it on fortress at a time.

The Emperor could've completed the Webway had he brought Magnus in earlier. Chaos took the opportunity to paralyze him on the throneworld with magnus breaking the Secret Project so early.

If you are bringing a second legion back to terra bring back the emperors children - that way fulgrim doesn’t turn due to the lair blade, ferris doesn’t go nuts wanting to kill him so the loyalists are technically up 2 legions and the traitors are down one

My guess for the original reason why rogal was chosen, is the emperor wanted rogal to fortify the webway as they claimed it. Plus if daemons were a problem rogals warp resistance would be a big help

NOOOO....He didn't know exactly what would happen. He knew there would eventually be a galactic turmoil, but he didn't know when and specifically who would turn. Rogal was to beef up the webway defenses. I imagine Rogal would have been assigned with going into the Webway and establishing fortifications on all external gates as well. The webway can only be secured if ALL doors are either locked or guarded.

Of course it makes sense, since he could see many possible outcomes. He put horus in charge because he knew whoever took the lead would fall, so he put the one who was most worthy for the position but one he could do with out. Gulliman needed to mantain Ultramar in the case the emperor failed. Now with the lion's book, when and why did he place the shield away for the lion? There was 4 possible outcomes, from what i see...death for humanity, the death of the imperium but life for ultramar, the emperor wins and the webway established, the webway fails and a new god must be born.

I am sure I read a short story with Malcador, or was it an audio book ? where he is talking to an Astropath about them manoeuvring the Primarch's to fight each other from the start..... that would suggest to me that both Malcador and The Emperor new that a civil war would brew. Maybe it was Chaos that twisted it subtly so that the Imperium wouldn't win ? I think it was called The First Lord of the Imperium ?

It could have been even simpler. he knew he would be cloistered up in the webway project, and thought it simple prudence to have fortifications while he in the custodians were busy.

The Emperor made it pretty clear how his foresight worked in Master of Mankind. The Emperor saw something would happen but not the specifics. He probably didn't see fully half the Imperial Army and Titan Legions turning, or Magnus breaking the wards of the Imperial Palace. He probably thought 3 or 4 Legions would turn and the situation would be manageable rather than the catastrophe it turned out to be.

Horus himself acknowledged Dorn as the greatest military commander of his brothers. Guilliman is a better leader overall and is probably the best primarch for almost anything that doesn't require him to fight, but he's not a better general than Dorn, and he's not smarter than Perturabo. Perturabo is less stable than Dorn, so Dorn is the obvious choice to defend the capital. Guilliman could better run the imperium, but against Perturabo he'd have lost.

I always believed that the Emperor not only knew, but actually planned on the heresy. It would have been a way of culling the Legions after they had conquered the galaxy, just as he culled the Thunder Warriors after they had conquered Terra. I just think he planned on winning easier as he forsaw 11 loyal legions vs 7 traitor (Thousand Sons and Alpha Legion were loyal)

This is just my own line of thinking, but on the topic of not bringing Guilliman to Terra, the main reason I can think is this: If the Emperor truly did foresee the Heresy, then he could have foreseen Imperium Secundus. If the method of Heresy was unknown to him, it stands to reason that he might have doubted Guilliman after seeing his future "second founding", mistaking that to be a product of betrayal. Likewise he could have seen the presence of the Fallen in a vision, therefore the Lion would be out. Dorn is the best choice purely because if he saw Dorn's death, he knows it would be in his service. Just my two cents anyway

They were a precaution from chaos interference or unexpected enemies in the webway.

At the risk of pointing out the obvious here, there is also the fact the Terra is the imperial fists home world. Their fortress monastery is on Terra at this time. Its where Rogal goes to chill, build, and prepare with his sons. Its also where the imperial fists recruit from to this day. Yes Rogal is great at building and defending, and whether he was there to do so against foes from the webway or the heresy is up for debate. But it doesn't change the fact that Terra is where the imperial fists always return at the end of a long campaign Rogal especially.

Even the Emperor knew Dorn wasnt cool enough to turn rebel.

Rogal, Roboute on defense, Lion and Russ on offensive Would’ve been great

I don't like the idea of the Emperor predicting the Horus Heresy. It undermines the essential humanity of him and his Primarchs as well as the brutal irony of the Imperium of Man. Brutal irony is the core theme of the entire Warhammer 40k setting.

If the primarchs are aspects of the emperor, it’s safe to say that like Sanguinius and Conrad, the emperor could see the future. My head canon is that the emperor saw the limitation of humanity during the Dark Age of Humanity when it came to the warp. At this time, humanity showed dominion over the physical galaxy, but we’re eventually overcome by the immaterium. The existence of the primarchs themselves are attempts by the emperor to dominate the immaterium.

I think once the Rangdan Xenocides ended, the Emperor knew that some of his sons would rise up and rebel against him. He was certain that the Ruinous Powers had some inroads into his sons. He knew Angron would definitely rebel, that it was highly likely that Kurze would descend into madness at take up arms against him, he was confident that Mortarion would rebel against him and I'm pretty sure he knew that Lorgar would rebel, especially after the razing of Monarchia. He was completely blindsided by Horus and Fulgrim falling to chaos and rebelling. He was also completely caught unawares by Tzeench tempting Magnus, giving him a power boost to break through the psychic wards and wrecking the webway project, which basically sidelined him for almost the entirety of the heresy. The primarchs the Emperor knew were 100% loyal pre-heresy were Horus Lupercal, Lion el'Johnson, Sanguinius, Roboutte Guilleman, Leman Russ, Vulcan, Alpharius, Fulgrim and Rogal Dorn. At the absolute most, he thought that there would be 5, maybe 6 primarchs, along with their legions who would rebel against him, and he thought he'd have the numbers to fight off the traitors, cull their legions then censure, imprison or execute their primarchs, he didn't foresee a full half of the Imperium rising up in revolt against him. Outside of the ones he knew for certain who would fall to the corruption of chaos and rebel, he questioned the loyalty of Corvus Corax, Omegon, Ferrus Manus and Jaghati Khan, he just didn't know with absolute certainty where their loyalties lay. The biggest limitation that Big E had at that time was that he still perceived things like a human.

The emperor knew that it was one of 2 sons that could organize the heresy. Horus or Gulliman. Just sent the Lion to go present that ring.

I think that Big E saw the Heresy coming, but didn't know exactly which of his sons would fall to chaos. While he may have had implicit trust in several of his sons, if there's one thing you can count on with the other primarchs, it's petty squabbling and jealousy getting in the way of duty. Guilliman would have tied Dorn up in too much bureaucratic red tape for him to have Terra fully fortified in time. Russ would have been just as likely to sabotage the fortifications or disobey Dorn's orders so he could have a less boring fight.

Dorn was probably just the least irritating Primarch As a chef I prefer people who keep their mouths shut and get on with things over people who complain or try to make unfunny jokes the whole time

The redundancy of the Primarchs are as follows: Lion El'Jonson - Horus Vulkan - Ferrus Manus Sanguinius - Fulgrim Dorn - Perturabo Corax - Curze Alpharius - J. Khan Gulliliman - Lorgar Russ - Angron Mortarion - Magnus

I think if it was Guliman back at terra that would have caused issues. Expecially considering how the high council went down.

I don't think the role of Ultramar for the Imperium can be overstated. The galaxy as a whole and the Ultima segmentum in particular is a big place and Ultramar is the one region reliably producing a surplus of resources. Without a functioning Ultramar the Imperium would have likely fallen milennia ago.

ok but the word bears did attack ultramare as far as foresight goes that does throw a wrench in bring their whole legion and what Gullimen had to go through to hold it they wouldnt have had reinforcements which is a huge part of his strategy

I think big e knew but didn't know who would fall and who wouldn't that's why he brought Rogal and I think he even knew about secundus that's why he didn't bring Guilliman

I "First Lord of the Imperium" Malcador, speaking with, if memory serves me well, the historitor his friend, clearly states that the primarch are means to an end, that the imperium was never ment for post humans (so no primarch and spaces marines) but for humans AND that the war that they were in was part of the plan since the beginning, to thin the herd (all 18 of them). The only thing out of control was that the forces of chaos made their move too early than what the Emperor expected. Not for a minute I thought that the heresy happened by mistake... it was part of the plan... in the book where the thrice cursed lupercal meet Russ, the future warmaster is clearly jelous, unable to cope with ONE of his brother, go figure when the other 18 (the two lost ones at that point were just missing, like all the other but lupercal and Russ)... I even bet the emperor, in a way or another, gat a role to play in the scattering of the infant primarch, to have each and every one lands on the intended planet... Dorn was recalled to Terra because the Emperor knew

i mean something i find interesting is rogal was if im not miss remembering the only one of the loyalist primarchs who actually killed there brother fully without leaving an opportunity to survive i mean even russ the emperors executioner had hesitated to kill there brother horus when he played its me your brother shtick and this is one of the people the emperor trusted unconditionally as pointed out in the video so possibly the emperor judged rogal the right man to be able to kill there brothers should push come to shove but thats only one interpritation

I think He put them there as fail safe ,if webway project failed he would have best defensive legion with geneseed most resistant of copuption of chaos (that Emoeror and Malkador know for sure) just for that he was best choise and all rest was just bonus benefits having Dorn and IV there

The emporer either knew and wanted it or he’d have just had Horus killed. Or he didn’t know.

Because the Black Library writers had to follow guidelines or lacked sound military and strategic knowledge to think of how super smart rulers and soldiers would actually conduct themselves in certain scenarios. Trying to make grim-dark and near perfect soldiers and strategists can't coincide because you'd end up with conflicts being prevented before they start or stalemates galore.

If you need a yellow builder, you don't call for a blue bureaucrat.

because if his plan worked out at some point 10000 Farsees would suddenly turn up to try and undo it.

I think a lot of these discussions are shaded by the fact that we knew that the heresy was coming. I think the emperor brought rogal back because as the crusade went further and further his sons were further and further unable to help him should something happen. The imperial fists are the best defensive legion. Their job was to make sure that no other brother chapter would be needed and both the emperor's goals and the crusades goals could happen without any concern for the empire's safety.

I've heard it said that some of the Primarchs expressed doubts about Horus being the best choice for Warmaster, or felt they were a better choice, but I've never heard of any of the Primarchs being jealous that Dorn was the only brother the Emperor took back to Terra with him. Was it not a big deal?

A siege in stalemate is a victory for the defender.

Big E should have brought Magnus to help alongside Dorn, the Emperor knew Magnus was completely loyal to him, Magnus himself never really betraying the Emperor, rather just being wreckless in his attempt to warm him, even after he had accepted his mistake and punishment, only faltering in the last moment as his sons were being slaughtered and Russ was attempting to kill him against the Emperor's wishs falling for Horus's lies. Even after magnus was shattered, they never joined the heresy, however it is true that shards of magus did join chaos, they can't be held the same as whole magnus I their judgment, even then there are loyal shards of magnus as well. If the Emperor called magnus to help with his web way project, not only could it possibly speed up progress, but magnus would never end up breaking the barriers, and if they did end up broken by some other means, then magnus could sit on the throne so malcador would not have to die, and big E could go put down the rebellion himself. It was implied that the Emperor wanted Russ to bring magnus to Terra for that very reason to sit on the throne so he could go fix things, as magnus was the only other one able to, malcador excluded as he could only do so for a short time before dying. With the barriers intact however the traitor forces would have been severely weakened without demonic aid, and the additional of powerful psykers that way have been allowed to use their powers in the crisis by the Emperor and the ability for he himself to walk the battle field, the heresy would have been over quicker then if Gman was there, though if the Emperor truely foresaw it, and wished to shop it he could have summoned all 3, dorn to fortify and defend, well Gman organized and lead, and Magnus supported the Emperor sitting on the throne if need be but the combined 3 legions, with an Emperor not bound to the throne could have potentially held even if every other legion turned.

In the short the Board is Set, Malcador and the Emperor discuss why Dorn was on Terra. In short Hydra Dominatus

I think the imperial Palace was meant to be fortified to protect from without as well as within in case something did go seriously wrong with the there would be a sufficient Force at least in theory to deal with

Big E: Dorn, my son, I need you to come to Terra and fortify the shit out of the Sol System. Dorn: Ok, why? Big E: Oh, no particular reason...

The best offense is a good defense

If the Emperor is going have a second legion why not Pertuabo? This would have push competition between the two brothers. Or why not Magnus? With his psychic power he would have been able to help with psychic defence and as well help with the webway project.

Big E should have brought Magnus as well with him to Terra. Directly prepare him and use him for the war in the webway. Keep him from doing stupid things like assaulting Terra psychicly (Magnus did that wrong!) and having one more loyal legion.

I believe Perterabo would have been a better choice. The Sol System would've been a massive Iron Cage. 🤷🏿‍♂️

It would make sense to recall only Dorn if the Emperor not only foresaw, but intended for the Heresy. The Emperor knew that he would need to become a god in order to fight Chaos, and so set up the most dramatic, psychically significant series of events possible. He needed his favorite son to betray and kill him, just like he was betrayed by previous warmasters. Horus was still Horus until very near the end, and would have seen a recall of multiple large legions as a setup. Nobody would think twice about pulling back the guy who fortifies things to fortify Terra. Dragging along the Ultramarines would have been a clear indicator to Horus that something was up and would likely have changed his plans. Nearly every single step of the Heresy, on both sides, pointed towards a dramatic personal confrontation, something that both Horus and the Emperor needed.

The question I had is why didn't he bring Magnus back to Terra. If the purpose was to work on the webway project then why not bring the primarch that was made to power the golden thrown? Rogal did his job, but Magnus never got the chance to do his job.