Currently the AI when it is in a vehicle only uses its main weapon, you can be next to an enemy tank that will only use its main weapon, in a future update I would like that in that hypothetical update it could shoot if it had the ability to have the suitable equipment (be it TNT packs or anti-tank weapons or whatever they have on hand) that they can use against their enemy, because actually you only can do it that manually, what I mean with this?, welp, thinking in units like AT,flamethrowers,etc. be able to use AI their second weapon while in vehicle too in case they can
