I really doubt that. How many coaches could uproot the playing styles and locker rooms of Barcelona, Bayern, and Manchester City? If it were so easy to turn a good team into a great team, then Chelsea wouldn't sack a coach per anum. With a little research it reveals that Bayern was no easy path, they resisted Pep's changes at every turn, and made it difficult to create his own team. They supported him financially to an extent but that's it, he was battling the board for his tenure.
To be marked by greatness one doesn't have to lift minnows to glory.