I agree with your overall assessment here. There's a huge attacking advantage with the air units.
There are a few leaders that can attack air units you can put in your locker room, but that's only one additional unit per fight.
Currently there is only one surface to air defense unit, the rocket launcher. That means that anyone who has flying units is basically indestructible. We have so many land defense units, many of which can do double duty as Sea defense units, but none of them can touch airborne targets. Without the addition of more surface to air defense units, any player with flying units is playing with a massive advantage. That's not fun for anyone. I'd suggest making the Rocket Salvo good against air units as well, and then adding a third unit for air defense. That would make for a significantly more balanced game. Also, it's ridiculous that bases do not have air defense capabilities as well. Base turrets ought to be good against all units.
Anti should have alot of hp. While using cobra. All I have to do is use baroness special attack. To defeat the anti air support.Going all the way left then right corner.