This shouldn't come as a big surprise to anybody who's read Education of a Coach. I don't recall any explicit references in there to coaches grooming their subordinates for future jobs, but that kind of ethos was implicit all the way through. Besides, if you're a teacher you're a teacher, and the book made it clear that BB-like coaches (and I suspect it's pretty universal) see themselves as teachers. (Both those who are kidding themselves and those who are not, actually.)