[@Burning Kitty] if you make a profile for the UNSC their history is yours, you have priority because you came first. Should someone make the Covenant later on they have to abide to your history if they want to include the UNSC

@Dead Cruiser well considering the existing factions have not interacted previously I dont see the problem. The galaxy is a large place, each faction having their own previous issues. It just so happens things are set in motion for them to meet