The danger of a promotion to a position within the same group is micromanagement. A person I know was in a position under a manager who had been promoted within the group and that manager was micromanaging. It's just not the most productive situation in the world.
About the only time I have been a supervisor has been in rock climbing and running situations. About all one can do is give the training (to the instructors or students or athletes) and then let them go. In climbing, while I was the director, I was also an instructor, and I found that being out of sight of the other instructors (on the other side of our climbing rock) allowed the other instructors to do good work. Yvon Chouinard would call that "management by absence". I think it is an effective method.
Runners on the other hand can be a little different. Students are typically young and as such can either be very competitive with each other or all not work hard enough. In other words, getting them to run the appropriate effort on any given day can be a little more difficult. Ultimately though it is up to each individual person as to what level of seriousness he or she wants to take the training, which takes the pressure off of the coaches desire to do the best we possibly can.
In short, if you manage, you have people who are getting paid to do a job, get out of the way and let them do their job. I must say, I suppose I am rather fortunate, I have never had a manager who I saw as micromanaging. I can not even think of one.