Instead of the lame plasma cannon replace it with a cannon or Missile that directly damages the hull regardless of armor but does less damage than conventional shells.
I made a armor piercing suggestion that vehicle damage increase instead allows 10% of the damage to go to the hull. this would be much more convenient for the developers and helps the rifleman class as a full time assault class. Also, I like Plasma, it has its place in the game. what I dislike about this idea has already been mentioned. it would be nearly impossible to balance, and it will always be complained about. (but I like that you are thinking about damaging the hull)
Complete hull damage means plasma is either always the best cannon, or always worse than the other cannons. It completely ignores all armor so that means you know exactly how many shots it takes to kill a tank, if that is fewer than any other cannon, plasma is the only thing worth getting, if that is more than any other cannon, the other cannon is better than plasma. You could try to balance it between the other weapons but what are you going to choose? A cannon which might be better than plasma, or a cannon that WILL be perfectly able to deal with anything the enemy throws at it? I don't mind the idea of it doing minor hull damage so that it is harder to repair and limits how long a tank can fight against it even with huge armor, but it shouldn't do all hull damage.
