As the title says, since the ingame APCs are basically utility vehicles in real life. This means that they can tow AA guns, AT guns and other supplies into the battlefield. Like the Soviet buildable AA have a wheeled chassis that be moved around. And all buildable AT guns in game for the factions can be towed too. Since APC squads lack engineers to reinforce the defensive/offensive position, we can remedy this by adding a third towable vehicle, a supply trailer, containing ammo and bandages to help friendly troops stay effective. (The supply trailer can be as fragile as the APC itself to prevent abuse.) Bellow is a image of a generic supply trailer from BFV’s cut content.
So why don’t we give the option to attach those trailers for our APCs when we spawn one on the battlefield, it could be a squad upgrade: you can choose what you would like to bring in, a AA trailer, a AT gun, or a supply trailer. Then you can detach those towables to wherever you like and strength the position to help friendly teams.