N is the number of managers I've personally reported to (directly and indirectly), other managers I've had direct experience with at my various workplaces, the managers of my peers at these workplaces, and the managers my friends at other companies have told me about.

I've seen many bad managers, but their flaws have been: political shenanigans, technological ignorance, lack of involvement, or just general cluelessness. The one thing I've never actually seen yet is a manager who is trying to do too much in the details.