That model looks great.
Also have it have a 4 second reload time
That's longer than the Tank's reload time. It's going to be almost impossible to hit anything if you have it like that.
The turret looks more like a flak/machine gun, so it should have a rapid fire/inaccuracy thing sort of like the Minigun. (it's easier to hit flying vehicles)
If possible, make it do 2x or 3x damage to vehicles, that would work very well.