4 groups, group 1: ground forces (tanks, Humvees, jeeps, light tanks, aa guns,etc).
group 2: heli/jet commandos(only task is to keep the skies open and to take down any/all jets or heli's that are in the skies)
group 3: infantryman (basically what you normally do no orders except when said on battlefield)
group 4: assassins or commander(assassins are the vanguards of the attack, only using silenced weapons, can give orders. commanders are the leaders of the platoon the can use what the want when they want they are in full command of everything.)