I created an account for the fun of it. I'm surrounded by Sacha's empire.
Welcome!
Is there any purpose to putting more than one arc in a fleet?
As fooder said, it just adds more population to the planet when it forms. Personally, I don't see much need to have more than 1 arc in a fleet any more. The only reason I can see is if you want to colonise close to enemy territory, adding a few arcs will mean it's harder for your opponent to take the planet. I guess also if you find a planet with above average iron production, that could be useful with more than 1 arc.
Where are you? So that I can add it to the list of players.