@teslas:
As is, AA guns shine at scaring your opponent into thinking “what if”. That is their main benefit, do not forget this.
At a cost of 5, AA guns are often not worth purchasing over 1.66 infantry units, even if your opponent has lots of planes, assuming you have a large defensive stack. For instance, if Germany has 15 planes coming, and Russia already has 4 AA guns to shoot at 12, they’re actually very likely better suited to buy infantry than an AA gun + infantry.
That’s a good summary of why AA guns as-is are poorly balanced in the negative direction. Even in optimal circumstances it’s not worth buying one, ever.
At a cost of 4, AA guns would become absolutely better than infantry, but not by a huge amount, in large battles with lots of attacking planes.
Shouldn’t they be, though? Enemy has lots of airplanes, you need to defend - if that’s not what AA is for, what is AA for?
At a cost of 3, AA guns would ����ing amazing, and you’d be seeing them be purchased much, much more often. A cost of 3 would be game-changing.
I think it’s worth a shot. As you noted even at a cost of 4 it would only be in specific battles way late into the game where an opponent commits a huge air force that it would be worth buying, and then only marginally so. So we have to bring the cost down to 3 to make them worth buying at all in any circumstance. If a unit exists in the game there should be some circumstance in which it’s worth buying it, no? There’s the threshold - cost of 3. It’s worth testing to see what happens IMO.