That's enough fun. Now on to something completely different.....
The best Managers ever give you what? 1WAR per year? If even that.
There is a good argument to make that teams shouldn't even use humans to make in-game decisions, and probably there is a game script prepared before the game that all teams use to follow through on.
JS, also has a legit brain trust behind him, helping him make those decisions. He is probably more like a CEO than a "free" thinker.
Managers' jobs are to motivate their players, protect their players from the media and effectively communicate their team's philosophy to the media. That is basically it. That is why Aaron Boone has managed multiple years for the Yankees.