Making managers

Maybe somebody out there knows more about this that me (certainly someone does), but I noted a very interesting thing about the Kansas City A's from 1962-65: Those teams had a LOT of players who would later become significant managers and/or coaches in major league baseball.
How did I start studying this? I looked up former St. Louis Browns, Kansas City As, Baltimore Orioles and Cleveland Indians general manager Hank Peters. The current crop of playoff-caliber Cleveland Indians is a direct descendant from Peters' handiwork, to wit:
Peters became the Indians general manager in 1988. As his assistant, he picked John Hart, a young former player her knew from Baltimore. When Peters fired manager Doc Edwards that summer (Let us note Edwards was one of the A's players I shall shortly list. He was team's primary catcher in 1963-64.), Peters replaced Edwards with Hart. Hart finished out the season and then was kicked upstairs to the front office, where Peters would groom him to be the next general manager.
Peters believed in player development, and Peters and Hart put together the core of the team that would win six American league central pennants in the 1990s and early 2000s. Hart trained as his replacement Mark Shapiro, who has been in place since 2001, and who used a player development oriented minor league system to rebuild the Indians after the 2002 season.
Thus, the modern Indians are the heirs of the 1970s and 1980s Baltimore Orioles teams overseen by Peters, building around home-grown players from a strong minor league player development system.
Now, back to where I started. Long about 1962. Peters had moved into Kansas City's front office as a director of scouting and minor league system a few years earlier. I went to check and see if the A's developed any superstar players while he was there.
If they did (and Reggie Jackson, Catfish Hunter and so on certainly were great players) they did not surface until after Peters left to return to the Browns, who were now the Baltimore Orioles, in 1965. However, it seems that Peters may have had one lasting effect on baseball: his team developed players who became major league coaches and managers at an amazing rate.
Baseball-reference.com has all sorts of interesting things on it, and that's where I found lists of the teams including the following names:
1. Tony LaRussa (manager)
2. Dick Howser (manager)
3. Doc Edwards (manager)
4. Ken Harrelson (manager)
5. Haywood Sullivan (manager, front office guy, owner)
6. Charlie Lau (hitting coach)
7. Dave Duncan (LaRussa's longtime pitching coach)
8. Bill Fischer (pitching coach)
9. Jack Aker (pitching coach)
There may be others I don't know. But, at the rate of nine managers and coaches on one team over three seasons, I doubt there has ever been teams as "baseball smart" as these were. Unfortunately, they only won 72, 73 and 57 games during those seasons.