He will drive the young talents away. How many young excellent talents have got a chance with Mourinho as manager? I don't think a single one ever got a fair chance. He moves to clubs that want success straight away and because of that young talents will never get a chance. The top class players he sign demands league wins and excellent CL results. His methods is so mentally weird that players only accept the methods when they win. I wonder how long time Zlatan for example will accept that Mourinho will hire detectives so he know what he do on his free time?
He did that at Real and I doubt that it didn't happen at his other clubs. Hire detectives to spy on the players and on his staff. He is the biggest control freak in world football. He is so afraid that what they do behind closed doors will leak to the press that must have total control, that his weird methods will leak out.
Man U now have a maniac as manager. The players will accept him but only if they win, win, win. If they for example finish in third place then he will lose the dressing room, no ifs or buts, he will lose the dressing room, again.
Young talents will never get a fair chance and will lose the dressing room, the question is when and not if it will happen.