He'll be taking over as a new manager for Benfica, but as you said, it's not right to expect him to suddenly wield a special magic wand. He'll get to know the players as much as he can and put the best players on the pitch. I believe he did his best in the Turkish league last year. Furthermore, Fenerbahçe's 18-year-old Yusuf Akçiçek's career took off thanks to him. Mourinho is a successful coach, providing young players with the opportunity to introduce them to the world.
I agree with you, Mourinho is indeed a great coach who his statistics and achievements has placed him in a high esteem. Although, with the current state of teams and new tactics in the game, I'm not expecting much from him anymore, he has done his part in football and has nothing to prove again. I still remember those good old days that if you're a manager and you're against a Mourinho team, especially that his Chelsea and Inter Milan team before 2010, you must pass through hell before you get to beat him.