Success breeds success. Barcelona and Bayern were already firmly established in the Champions League with financial backing most clubs can only dream of. Players queue up to join them no matter who is in charge. Pep knew Barcelona inside when he took over and he made a name for himself by taking what was there and elevating it further, he did a great job. He left and Barcelona continued without him despite the team needing an overhaul.
He took control of Bayern Munich, who more often than not, batter the rest of the Bundesliga into submission year after year. He maintained the status quo while not exactly setting Europe alight. He has done a good job. When he leaves, Bayern Munich will continue without him as if nothing has happened.
He will take control of Manchester City, who will undoubtedly give him a war chest of significant proportions to work his magic. Yes, it will be another feather in his cap if Manchester City finally get a better return on the squillions they have pissed away. But to me he achieves the bare minimum that the stature of the clubs he has managed expect. Nothing more, nothing less. He ain't no Clough.
The Champions League? It's been a closed shop for years with the same teams playing each other year after year. As I said, success breeds success. He should be winning it with the resources he has had. Spurs winning it. Now that would be of merit.