This could be a modified rifle squad with say seven riflemen armed with M1 garand, one BAR gunner, one mortarman and one anti tank man (bazooka)
There would be a defensive rifle squad choice that would spawn somewhat near the maproom, but would still have to move into position for defense.
Also, along with the "troop" loadout there would be an offensive rifle squad load out
When the player selects a troop carrier and chooses "troops", it is the same as it is now. Troops have no action but to run to the maproom.
If the player selects Rifle squad, as soon as the squad is deployed, the carrying vehicle disappears and the player becomes the squad leader with 9 "drones" so to speak. The drones advance with and cover the squad leader and drop to a defensive prone position each time the leader stops.
The player could switch positions as they do with bomber drones and the selected position becomes the squad leader. If the squad leader is killed, he rotates to the next position as happens currently with bomber drones.
In the case of a "manned" squad, only the squad leader needs to enter the maproom for a successful capture, however defensive squads cannot be elminated by porking the barracks, so the defenders will always retain this capability until the base is captured by the enemy.
Once the defensive squad is all killed however, they may not be able to respawn and get into position quickly enough to prevent capture.