[Targan]

In my last Twilight campaign there was a definite divide between the longest-serving members of the unit and the various newcomers. It fits well with reality but it wasn't artificial. There were definite trust issues with some of the newcomers, and also the newcomers were often pretty horrified at the unit's modus operandi, particularly after command passed to Major Anthony Po.

Sometimes there was movement of personnel between allied units too, often at the request of those being transferred. I think that forestalled a few instances of desertion. When Major Po's group encountered Captain Molly Warren's B Troop, 116th ACR at Dobrodzien there was a great deal of suspicion on both sides, although that was slightly mitigated by a few characters (PCs and NPCs) having met at other times during the war.

Major Po eventually tried to combine the two units and take overall command, but it didn't last very long. There was a brief civil war following a botched raid on the outskirts of Krakow, and the two units went their separate ways. A few personnel from both sides stayed with the respective new units. I think the legalities of who was technically in a state of desertion in a case like that would get very murky.

Taking it upon yourself to move to a different unit, with the permission of the receiving unit but not the original unit... I guess it would in that case come down to whether Captain Warren was found to be guilty of refusing Major Po's lawful orders or not. Warren's people were fiercely loyal to her and almost to a man ignored Po's orders once Warren was in conflict with him. Po's people had far more varied reasons for remaining loyal to him, but mostly it was fear.