Hello.

Don't know why noone mentioned it or never asked a GM about it, but you DON'T need to have all rep same time. This means if you are close to revered with Cartel when you start doing this, going for Bloodsail rep first is a very stupid thing to do. You want to complete Cartel first, then get bloodsail. You will still get credit (I have talked to GM and saw some armory page with this achievement and cartel in hated).