I have to agree with StaticSails, the shooting animation is very awkward, way more cartoonish than it needs to. Unless you wanna go for that, perhaps you should rather go for a more realistic shooting animation that does not have a distortion on the cannon, rather simply a short cocking motion of the cannon, followed by the top half also retracting, and then slowly both return to their default positions. That would work better, I think.
As a design choice, maybe you could deviate a little from one tank to the other, like the green one could have an antenna on one side, while the blue one has a radome, or male the blue one more angular; you know, little differences like that.