I'm guessing that the hobo looking German is 'scavenger', the tank commander is 'elite armor', and the german with protective glasses is 'fortification'.
These are the other three rare US commanders. I still have no idea what they are. One of them has an 'easy-eight' sherman call-in.
Elite Armored Doctrine (Signal Relay, Emergency Repairs, HEAT shells, Panzer Commander, and Vet P4 Ausf J. Battle Group)
Scavenge Doctrine (Thorough Salvage, Jaeger Light Inf Recon Squad, Infiltration Tactics, Flakpanzer IV Ostwind, and 105mm Howitzer Barrage)
Fortifications Doctrine (MG34 MG Team, Heavy Fortifications, Field Defenses - Mines / Bunkers, Pak 43 Emplacement, and Zeroing Artillery)