Okay so I understand that usually it goes first player as M.C., then 2nd player is the arbiter, but why can't I be master chief in the halo 3 campaign in co-op online. Even when i am party leader. I have done everything I can think of. I have a higher rank, more achievements, and just as an idea I beat the campaign on legendary by myself when my friends haven't. Please, I'm out of ideas and it's just really annoying so if anyone has any ideas...