Our wingers are suited to his style of play? I am assuming those wingers at Sporting must be working very hard in both attack and defence. Antony and Garnacho will be fine but will Rashford be able to play that role?
The "advantage" of this system is that, while the wide players will have to run A LOT up and down the field, their defensive responsibilities won't be as heavy as if they were actual fullbacks, because the CBs will help cover the sides.
So yes, they're gonna have to work a lot running up and down the field, they're not going to be "locked" into certain zones like fullbacks or wingers. They're creating and exploring gaps in the opponents' defensive line.
You don't think Rashford and Garnacho will be wing backs, do you?
You would be surprised how some players adapt to those roles.
His preference at Sporting was using wingers in those roles. Geny, Nuno Santos, Quenda, Maxi, they're all more wingers than fullbacks.
Maxi Araujo for example, played as winger in Toluca. In his 1st games he had a few difficulties tracking back and covering the players in his areas, but that has improved. Against city he was very good in marking savinho.
So while I get your concerns, don't sell the players short, they might be more capable than we expect.