It's a weapon? It could be, but I wouldn't want us to play Fellaini's way
.
Well it could be the way you wanted if we played an aggressive frontline not allowing time and space for them to play at the back. They'd be forced to play long, giving us the aerial advantage in the midle. But you cannot play a high pressing game, all game, all season (Abe Lincoln said that
). So during a game you could switch between high pressure and relentless attack to sitting back and waiting for the mistake.
Pressing frontline: Sanchez - Lukaku - Lingaard (granted, Lukaku may not be ideal for this...)
They play a back three, so Shaw and Valencia will only need to concentrate on the wingbacks. That leaves a man for man midfield which I think Fellaini, Pogba and Fred would dominate high and low. Ideally I´d have Matic for Fred as a defensive midfielder, as he'd be more apt to dropping into our backline, freeing our centre backs to drift a bit wider. But as it stands, I think it'll be Fellaini at defensive duties performing a similar task.
In a Mourinho point of view, when they do manage to get the ball to their midfielders, it'll be just the kind of football he thrives against (8th most touches, also 8th most passes in PL). Letting them play ball and waiting for a mistake. They've got a solid ball playing central midfield, and Fellaini is better at disrupting that than given credit for. Outside our defense, him, Pogba (both joint with 5) and Sanchez (6) has made the most tackles in the team this year. We would punish any mistake by hitting them at the break. Both Fred and Pogba will have the tempo and energy for it.
Bennet and Neves both have 9 fouls each, one less than the PL joint 4th most fouls. These are players in deep positions, so either they adapt and we create chances or Fellaini will be a weapon on set-pieces.