One of the tricky things - as a fan ... is that leadership becomes media narrative as much as anything. The guys who talk to the press get conflated with the leaders.
I mean leadership in these setting is often not the "inches we seek are everywhere" sort of speeches. Leadership is the 1987 Celtics seeing how hard it was for Kevin McHale to put on his shoes as he was playing the Finals with a broken foot (a foot that progressively got worse).
In baseball, the manager can establish a working environment. As I maintain - a baseball manager is the most like a boss someone would have in a real-life job ... delegate, coach the coaches, yada yada