I left this thread open as long as possible because this is a conversation the community needs to have, at least once. Now that the two parties have run their course and resorted to petty insults, we can lock it.
Anvil Game Studios' policy regarding regimental names is to not get involved at all to avoid playing favourites. It is up to the community itself to sort out who has the stronger claim and in the past, the offending party usually backed down peacefully. The actual rule given on the forum is that these disputes should be handled in private by the concerned parties and not turn into public spectacles.
The only time moderation has intervened was when entire threads - text and images - were plagiarized.