I think it would be really cool if there was a feature where players have a leadership Stat or Trait or even a player specialty where if they were made a captain, depending on their leadership Stat, it would have an effect on the performance of the team. If a player with a higher leadership was captain, the team performs better. If the stat was low, they perform worse.
The leadership stat has been suggested here before (see Revised Captaincy System)
A leadership speciality is certainly a good suggestion, if there is to be a new captaincy system