In this game we get to buy our units, distributing our points as we see fit. If you buy too much of one thing, you don't get enough of something else. I have no problem if one of my opponents does this sort of thing. If he buys ten bazookas he hasn't got any mortars or machine guns, for example, and my infantry will kill his bazooka teams.
If my opponent buys 10 AA guns for ground defence, that's okay, I'll mortar them or kill them with medium to heavy armour.
Bottom line, I let real world tactics take care of imbalances in my opponents line up. If I am unsuccessful, that's my poor play - not a signal to cry "gamey"!
Don't sweat it Croda, as others have pointed out here, I expect your opponents arty / mortar / armour will resolve the issue. :^)
OberGrupenStompinFeuhrer