The USMC works hard on cross-training to reduce costs, meaning that they can go out and complete short term objectives using fewer guys than other groups might need.
My MOS was a 2844, which was a Ground Radio Technician. I could repair and operate every radio the USMC had at an advanced level. I then received courses on how to provide EMT-level care on the battlefield, machine gunners school, vehicle operations (command, gunning, operation, egress, maneuvers), basic generator troubleshooting, vehicle maintenance training, artillery/medevac coordination, advanced SatComm training, etc... This is specifically so that teams are a) self-sustaining (one team can accomplish many jobs outside of their primary job) and b) to reduce the number of on-hand resources the USMC requires to function.
