I will say this, our tactics change with who is your escort and who is the convoy commander. When the Marines are your escort they return fire in such an aggressive manner that the enemy will often wait for another group to come by.
Over there you shoot at a Marine and they will do all that is possible to kill you. Makes a driver feel good to have a Marine escort. Don't get me wrong though, our troops all shoot the hell out of em when shot at but the Marines just shoot straighter.