It sorta is broken. Not even on wow does a 1v1 pvp battle last as long as they do on disco. When i say armour should have a downside, I am not saying it should be debiliating. If it is there would be no point at all.
Actually I just had what I consider a bright idea. Why not have the armour upgrades take up your thruster slot? Speed burst vs. damage tanking. For this idea to work all caps would need thrusters, but it would not be unbalanced because a faster moving cap will have less armour anyway.