Why wouldnt it stack?
The assault doctrine states that it doesn't stack unless the rules specifically states it stacks. It was most likely intended to stack and will be FAQed. But right now it does not say it stacks with the Assault Doctrine. So it doesn't stack. :/ According to The Chef from Tabletop Tactics anyway.
I disagree. Why should they do that? I like getting another boost turn 3+. No need to hold your reserves back this long if you think it's not worth it but you should still have other units around once you enter turn 3 who can benefit from it. The Assault Doctrine turns basically every of our units into a melee unit be it Intercessors, Tacticals or even Devastators.
I suppose it adds additional flare to the armies they apply to. And it does kind of push people into wanting to at least try to run mono-armies. For some it is really good and others it is kind of lack-luster. I understand the benefits of having +1A from Turn 3 onwards but every batrep I've seen, especially in competitive games, by T3 there is not much left on the board. You're getting washed out by T2 or you're both completely devastated. I just don't think having that +1 attack is going to amount to much. Especially with an army that wants to be in the opponents lines T2 at the latest. Just a personal opinion though. I think it is super fluffy as the Red Thirst starts to affect the army as the battle goes on. Meh I dunno. I was just throwing a thought out to the wind really.
But removing the bonus doesn't help with being defeated turn 3? That's pretty flawed logic.
Also competetive games have the problem of sticking to ITC which is kind of weird anyway. When using CA18 missions and proper terrain games shouldn't be over by turn 3 anymore. I know none of my games are unless it's a REALLY onesided match.
I’ll give you my full support in this. I attended a 5 game tournament 2 months ago. There was progressive end of battle round scoring and great terrain on all tables.
None of my 5 games were determined by turn 3.
Most were so very close until turn 4 or 5 and determined in those two turns. My final score was 3-1-1 and the game with the draw was determined in the last player turn, battle round 6.
Terrain is so important, and IMO, too few people acknowledge this.