Obviously the Zombies add rules. The question is, what have they added those rules to? And the answer is a simplified version of A&A.
Why do you think SBRs, new ICs, AAAs, etc were not included?
- Because WotC thought this would improve the game for seasoned players?
- because they wanted a more newb friendly product?
You can believe what you want, but I’m going with 2).
As for the complaint that the Pacific theatre is downplayed, that sounds like almost every A&A game I’ve ever played. It’s almost always KGF. If you don’t like that, I (again) recommend using your Zombies as a 1942.2 expansion. The base game was clearly not intended for those of us who want a deeper experience. I’m surprised anybody here is even playing it, other than to get a feel for the new mechanics.