I think a chief coach of a soccer team is a modern general. It’s because soccer is one of the most strategical sports in the world. A high degree of freedom hide causes of events and a lot of members make it difficult to control a team.
General must be a leader, therefore they can be good examples for passionate leaders.
Especially, coaches in European football league are special, they are in really harsh situation. They have many games every year and many players are traded each other so team member is always not fixed.
A few coaches who keep on getting a result even in this situation, are genuine. They are good examples for studying what is leadership.