Keep in mind, AA 88s won't be useful at low altitudes (I'm pretty sure) and plus just make them unmanned.
That being said, I do think we need an improvement of the logic for the AA. It seems that it should act more like the WWII ack gunners. I'm reading through The Wild Blue and it seems gunners would put up a lot of ack in a sheet/box and make bombers fly through that, getting pelted the entire way. Fighters could avoid that much easier, bombers would be much less effective. I think one or two at medium airfields and 3 or 4 at large is reasonable.