Fangio was a leader in the sense that the team seemed to respect him and continue playing hard for him. We all define leadership in different ways, but one of Fangio's few strengths was that he was a confident, decisive leader. Which tells me that leadership is only one piece of the puzzle, because Fangio lacked the rest of it.
Quinn may well be a good leader, but that does not mean that he will bring us the success we want. He couldn't do it with a superstar offense.