2 ideas:
1. Possibly create a way for officers of mustering regiments to message soldiers not yet in companies asking them to help form? Something like that, maybe you send a form to them or something basically like a recruitment drive for X company etc.
2. Perhaps order the list of 'Roles' by order of importance? IE Company Command is the highest with things like officer, nco, enlisted following it and ones like cook at the very bottom, just making it a bit easier to sort through