Indeed, Arcaea didn't get where they are now alone. They might have been alone at some point, but not since a while.
I believe the last time Arcaea was truly alone was right before they signed a mercenary agreement with Arcachon under Trinity. Since then Arcaea's always had if not allies then friends in high places. You really can't achieve anything in this game alone, as you at least need enough people who don't hate you enough to make sure they don't all ally to take you down.
