[Imp]

I used to play a guy that liked using helos, the totally gamey easy defence is to buy loads of the cheapest fast AA armed vehicle. Just swarm him driving the survivors adjacent before opening fire. Heavy losses but they are so cheap you will win. Becomes harder if they have TI but if most don't you can hide behind your wrecks to help close range.

Your really just doing what most people do with helos, draw fire with the cheaper stuff to protect the important ones.