Ayy I've been reading your thread concerning the Soviet Commander Revamp and can't help but notice you said Commissar Squads do not exist in the game. They are in fact already a fully implemented unit in the game and you can play with them in certain Theatre of War missions. The Commissar Squad is a 4 man squad comprising of 3 Conscripts and a Commissar.
Any unit buffed by Commissars cannot retreat in the Theatre of War scenario. I believe the mission is called "No retreat, No surrender".