the thing is, many people--not necessarily you--are confused about what a leader is. Being a leader is not about yelling and screaming and showing up your teammates. It's about leading by example, and inspiring others to work hard and achieve excellence. It's about making sure that everyone is of one mind with regard to the goals of each play, of each game, of the season. It's to sooth egos and diffuse conflict in the locker room. Basically, being a leader on any level, in any environemnt, is no different than being a third-grade teacher.
We won't see Vince yelling and screaming during games. We'll hear more about him trying to be a teacher than being a rabble-rouser. We'll still see him smiling and joking with the opposition. Those things won't be indicative that he is a poor leader.
For starters, his teammates have to ready to accept him as the leader, and defer to his wisdom and judgment. So far, at least, it seems like they are doing that.
However, to be a leader, you can't go into long funks or fall into a depression where you become overly introverted. You have to be a consistent communicator. Many people--like Josh Boone, for example--could never do that. I am a terrible leader for that reason. You can't get distracted. Can Vince do that? Who knows.