The BB coaching tree thing has something to do with TFB. I think that BB is the GOAT HC, but also that TFB made the coaching easier for all the coaches. Some of these coaches probably believed TFB had little to do with the success. So they bring what they think BB as HC was doing to a new team and fail sometimes spectacularly. BB always knew that having TFB helped and that is why BB is the GOAT HC. That is not to say that BB will not be able to reach the summit without TFB, I think he will, just not as consistently.