Why have you suggested Fiorentina or Napoli? Why not go all in and manage Colchester? Why the easy mode?
Again, he doesn't need to do it. He doesn't have to prove anything to anyone.
If anything else, have you watched Man City? I have never seen a team as well drilled as them. I am not saying better, or more impressive. But his style is clear to see. And to me (and the board of Barcelona, Bayern and Man City) that is enough evidence without even going into his trophy cabinet.