In the end, at least from what I have experienced, no one in the community seems to be overly concerned with what you do with your force. Sure, if you want to do a specific force that has listed equipment then you can, but you can also modify the story a bit to say, 'well, this is what remains after a battle' or 'there was a small group that did their own thing' or 'this equipment fractured off from the main force'. Similar to fighters in WWII (and now to an extent) with people painting stuff on their planes I am sure that would be even more escalated in the future when your military command might be light years away and cannot verify your paint scheme is per specification every month.