Yep, it's fine. It used to be that registered multis had to be in the same faction. Now there are no restrictions on that so they can be in the same or in different factions.
This is weird, In other online games I play a multi-account is when One person has multiple accounts, Other games often call this "Same computer usage" :)
That is true, but in this game, you are allowed only one account per player. Most MMORPGs I play don't even allow shared IPs for their games. but when you pay 30/month I can agree on it. So the question was answered, anything else use DMs.