When I was a kid, they used to say there was two successful types of MAJOR LEAGUE managers: The guy who did it a high level in the majors as a player and commanded respect for THAT (see Frank Robinson and Joe Torre). And, the guy who had the physical size that he just intimidated you by standing close to you (see Dallas Green). But, if you look around the MAJORS today, that's changed. Now, it's the guy who can navigate the egos of millionaires, follow instructions from the front office, one who doesn't need to be the one to get credit for success and keeps calm and answers all the questions at the daily TV post-game press conference.
Not sure about the minors? Used to be the guy who could baby sit and teach players how to act and play like a professional. Didn't need to be a former star or an intimidating monster. I think the role in the minors is still the same.