I don't do tanks in this game, but how have other games solved it ?
In other games the objective is to move somewhere both adversaries want in order capture or defend, and going there is equal to move away from safety to gain points for capture of objects, within the total capture object.
You need to capture more than one object to win a field, you also get activity points in some games, and sitting and camping gives you nothing for doing that except the tank you destroyed.
When you shoot, you must scoot away because cannon smoke will reveal you, both from ground and air, and that equals to move or get incoming within a few seconds.