The Story :
after 5 years listening to the trailer, i wondered if there are any clean version (or at least an original upload/soundtrack of it). Surprisingly there are none, so i decided to do it myself.
There's another version of this that doesn't have a good audio, granted the dude tried to drown the sounds of flaks and cannons, and i ran into the same problem too. This is the best one i could get from multiple attempts using karaoke apps (there were still exploding flak noises, some faint cannon sounds and a little bit of Churchill's infamous speech)
---------------------------------------------------NOTE!! ----------------------------------------------------------
This music doesn't belong to me and i don't take credits for this.
This music belongs to whoever makes this (i know its abrupt, but War Thunder dev themselves didn't even put a link to the "supposed" composer (maybe the War Thunder team were the creator)).
for those people who have also searched for this music and found nothing, you can rest now.