It will be 1 or the other I think unless he goes for a 433 In which would sound absolutely crazy on paper... But here me out.
Martial - Ibra - Mahrez
Rooney - Schneiderlin
Fellaini
Shaw - Mustafi - Mike - Valencia
David
But that is a very strong and powerful Midfield 3. Won't be the most technical or ball playing midfield ever but one of the most physicalist. In all honesty that front 3 if we sign Ibra and Mahrez wouldn't really need a ball playing or technical midfield. Martial & Mahrez are arguably the most creative and productive wingers in the league and Ibra is one of the worlds best finishers.
Schneiderlin in his Southampton days played as the box to box which is where all the interest from all the top teams came from, he is limited as a holding Mid and doesn't allow him to show his true colours.
I'd be happy for Rooney to spray that diagnol ball to Mahrez and watch him make fun of defenders. Rooney will probably grow into this midfield role and bag 10 goals and 10 assists in all competitions next season.
Fellaini who is probably the most hated player in this current United squad can do what he does best (not elbowing people) Chesting the ball down and playing it. Just let him sit in the CDM role and chest it down or try to head it, Tbf he actually isn't as bad on the ball as some make out. He has actually been pretty solid this season bar 1 or 2 performances.
I can see every physical player thriving under Mourinho. We would actually be an intimidating team again; Ibra, Rooney, Felli, Smalling, Schneiderlin, Valencia are all big strong lads. Then you have the wide areas as a huge threat with Martial and Mahrez doing there thing and King Dave in goal stopping everything.
If you took the time to read, what are your thoughts on a Physical United side under Mourinho?