Before entering the meeting with the other powerhouses, Quinn was to choose two people to take in with him, and two only. This was the same for the others as well. They were usually there as advisors, or future successors to the family. The other option was someone who was considered strong themselves.
When deciding who to bring with him, Quinn's first choice was Sam. Although Quinn hadn't known Sam too long compared to some of the others, Quinn not only trusted him but, Sam ran nearly everything that went on in the Cursed ship.
Quite frankly, without him, Quinn felt like his life on the Cursed ship would have been ten times harder. This was the obvious choice, but with the second person he was struggling. Usually with something like this, he would have liked to have taken one of his close friends, but where were they all?