I want to preface this by saying that I am on the spectrum and it struggle with tone, this comment isn't meant to be hostile , and more of a perspective from a "high level painter" versus someone more interested in army painting. I also want to state that unlike Trovarion I have not entered into competitions, although I am working on a piece to enter into Golden Demon Youngbloods next year or the year after. The blue wash absolutely did something. I'm a traditional artist as well as a miniature painter and colour theory is something that is a huge interest of mine. There are some areas on the metal that the blue is visible on its own that you missed, but It also mixes with the brown and creates a more complex looking colour. Blue cancels out the orange in brown is some areas, it makes it more de-saturated in some areas in a way that just a darker brown wouldn't do and creates a really nice tarnished look. It also bothered me when you said that you could just use agrax earthshade. The tone and colour of agrax are very different from the brown ink (the brown ink is warmer and less dark), and using a standard wash would not give you as much control over the paint. You could but it would look much worse up close than Trovarions. (I do agree that he should have taken the panel lines quite a bit darker though, and the edges should be brighter) Higher level miniature painting is all about having control over the paint, the colour it produces, and how it behaves on the model. The reason he used a smaller makeup style brush and a sponge is also control. Control of the texture and where the paint is going that you wont get just using a bigger drybrush. I do agree that airbushing and using chipping fluid was dumb. He should have skipped the chipping fluid and the airbrush, and chipped manually. You did say that you shouldn't go straight to yellow, which is almost always true, but using chipping fluid is an exception to that rule. You cant do a white first because it will show when chipping. However he should have skipped the chipping fluid entirely, it never looks good. Doing a white and using imperial fist contrast isn't quite how I would do it but its close. I would do a white, do a light wash with a very bright magenta, then use imperial fist. It doesent take much longer and adds some really nice orange tones. I highly recommend you try it. Much of your issue with this tutorial seems to be that Trovarion is trying to create something that is somewhat fast, but looks good very close, and pretty alright far away with lots of colour variation and texture. Trovarions miniature contains varied colours, textures, and detail that you would completely miss on the table. Your goal with painting more seems to be something fast that looks good on a table top. Sacrificing the nuance for more speed and less effort, achieving a high contrast and high impact look. Trovarions tutorial wasn't a bad video, its just not for you. Understanding the target audience of a video is very important when looking for tutorials and a skill many should work on. I'm not watching midwinter minis to help with my competition piece for example.

I'll be honest I don't know Trovarion but it did seem like the mini was unfinished. There are easily little details to have ben picked out like you said. And from someone of that caliber, you certainly would expect that. the face though, that face is on point.

if the blue wash does nothing then prove it, grab some minis and paint them up.

I was wondering why Iron warriors but it makes sense right they are rhe ultimate test of patience. You can finish one in 5 minutes and the rest is styling. Even the hazard stripres are optional when you think about it. (Even dawn of war didnt had them)

I agree with you. When I first saw that video, I also had mixed feelings. I would only say that I understand he does some things wrong at the beginning to show what is wrong then what is right. Also, I am sure that starting with the blue wash / glaze can be interresting... if you do not put that many things on it after. Finally, if had done that miniature, I would never have shown it and say it is finished. I would feel ashmed and want to hide in a hole for decades.