maybe overdrive should be separated into alterations: you could use the alterations on your hull, gun and module. By using the alteration, you raise all the traits of your tank by 50% or so, but for each alteration you use (the alterations on each part of the tank are separate), your hp goes down by 25%. if you use all three of the alterations, you might have an extraordinary tank, but it might go down with not so many hits. an example of where this might be useful is for a sniper: since he can be hard to shoot at, the low hp might no matter.