If you take someone like Raylan, he may have the control of his powers and all the skills to be an leader. But he is no way ready to lead mentally. His reckless, irrational, irresponsible behavior makes him in no way a viable leader mentally. 

To a lesser extent the same can be said for Astrid. She's been around for years and as a result she's got the control and skills to be a team leader. But I don't think she's ready mentally for hat kinda role.

I really the idea of type character. Make sense?