That's got nothing to do with quality of manager. Have you ever watched Arsenal play? They weave all their lovely patterns, but normally lack an end product. Same with Barcelona, they just pass from side to side and side to side until Messi shows up to make some magic. That is not managerial greatness. Let's look at AvB's Chelsea. They had some flair sure, but it's not fun watching a team when you know there is every chance that they could just fall apart at any time.
Compared to last year, Tottenham gone backwards. The only thing that has improved is Bale. Everyone always talks about how van Persie has had the largest impact in terms of winning Man U games, but he just scores goals by being in the right place at the right time. Bale has scored so so so many last minute goals to win games, not just from being in the right place and the chance being created due to a build up of pressure, but pieces of individual brilliance (like the last match) that have nothing to do with the manager
AVB's Porto was a wonder to see. Hulk, Falcao, Varela. If you think teams playing nice doesn't reflect the managerial qualities you should check your knowledge on soccer.
Barcelona team lacks a robust defensive line that in the firs 3 seasons help them dominate every team they played in Europe. If all you see in Barcelona game is just boring passes until Messi shows up you're one of the folks that rather watch highlights of a game than the whole thing.
Arsenal always had that English back end, phisically though but the qualities didn't match the front end. Tottenham has a horrible defense my god they can't hold an advantage for the sake of their lives.
Playing beautiful is a Philosophy and an ideal. Mourinho's ideal is to win. Everybody wants to win, but I will never pay a ticket to watch Mourinho's team score a goal and park the bus in front of the goal for the remainder of the match. On the other hand AVB's team resemble Mourinho's style but he couples them with some flair, which Mourinho doesn't like.