That's one loyal man.
GSP got boxing lessons from Freddie Roach. John Dannaher (sp) was his BJJ. And he obviously trained with Tristar (at one point he also trained with Jackson's).
Dude has money and could afford the best coaching/facilities. I agree SBG doesn't have much talent in major MMA besides Bellator (maybe?).
At this point, ATT is a better training environment. They got Moraes, Masvidal, Porier, Harrison, Nunes (both), Santos, Rakic, Texeira, Arloski, Rozenstruik, etc. They obviously had JJ before. And Colby. Mike B has proven his competence.
I laughed when I saw Conor went with Kavanah for the Floyd fight. This dude literally went back to back coaching his guy against one of the greatest boxers and then one of the best MMA grapplers of all time.
Right now, Trevor Whitman and Eugene Bareman are the best coaches right now in MMA.