Take it you're assuming that we don't bring anybody else in mate.
I think the back 4 will take care of itself (other than resting players) once everyone is fit.
But I believe he will swap and change the midfield and attack to suit the opposition. So I can't see it being a 1 fix suits all scenario as you suggest. Plus there are a lot of games to play so rotation will play a part to keep players fresh. For instance, I can't see all 3 of Klaassen, Rooney and Sigurdsson starting many matches, but 2 of the 3 will be starters in most. Think we'll bring in a new forward who will rotate with DCL. And when Bolasie is fit I can see him rotating with Sandro, with Lookman and Mirallas as back up. Some games we'll play 3 defensive minded midfielders. Some games we'll play 4231, others 433, and others a diamond with 2 up top. I really think we'll mix it up depending on the opposition.
Or that's what I'm hoping is going to happen anyway.