Mourinhos Porto side didn't have better players than Man U. There were a few teams in that CL that had better players on paper. They were very tactically defensive and clinical when it came to taking chances. They got lucky with the draw too. His Chelsea sides were better but similar in terms of being clinical. His Inter side wasn't a stand out team on paper either but he got the better of Pep by playing defensive at home and countering quickly up the wings, avoiding the Barca press and hitting them on the flanks where they were weak, then parking the bus in the away leg.

Agree that Pep had better players at Barca than Fergie at Man U in the 2 CL finals, but tactically Fergie was outdone also. He had no answer to the Barca press and no way of winning the ball back from them. He could have tried to switch the play like Mourinho's Inter did or to try and press Barca, which nobody really did at the time but which some teams try nowadays against Pep's sides with a great degree of success. But with Xavi, Iniesta and Messi in those sides the result was inevitable imo. 

Fergie in his latter years recognised that he was past it in the coaching department and used the likes of McClaren and Queiroz to do the day to day tactical/coaching stuff with his players. Something Wenger never did.

Reading this thread has got me thinking about the most successful British managers since the 1960s.  Almost without exception, they were born in Scotland or the north east of England. In no particular order, Don Revie, Bill Shankly, Jock Stein, Bobby Robson, Alex Ferguson, Matt Busby, Howard Kendall, Harry Catterick, Brian Clough, Kenny Dalglish, Bob Paisley, George Graham. All the aforementioned have won at least 3 trophies.  Add to the list Lawrie McMenemy and Bob Stokoe who both won FA Cups with second division sides against far superior opposition.