The tank thing is an issue with the preferred target because templates were used.
Don't forget, the devs had all tanks classed the same until Drawde made use of the helicopter class or light armor and the Ship class for heavy armor.
But we need to get these fixed eventually. Marmon Herrington should rape infantry, NOT tanks. Same for Vikers tank. When it encounters heavies, it should just pop smoke. At least, if it were dealing with humans, that will blind them or conceal it. Same goes for all 'Helicopter' classed tanks. Although I fear it will think its actually engaging them and move in for the 'kill' with smoke.
Maybe in time, a working smoke code will make this work for bot tanks too.
I could tell you why bots do everything and exactly who fixed what or broke what - The whole story. I just can't code for shit.