Have you played in a 4-3-3 recently?
The outside backs are responsible for getting forward on offense. Defensively you give up the space on the outside and protect the middle of the park with your 3 center mids - your wingers (TH14 and LeToux) are suppose to track back and pressure any outside play.
In your lineup below, you can play it 2 ways, have Rafa as a holding DCM with Dax and Lindpere as the offensive mids to support the forwards, or have Dax and and Lindpere hold with Rafa as the CAM. You would never have Lindpere and Dax play as true wingers and have Rafa alone in the center.
Understood, and absolutely not saying they would play as true wingers, just think it exposes Marquez to more space which his mobility can't handle. Not a huge difference but definitely a difference compared to being in the middle. The problem with Marquez is that I think his best position is being handled extremely well by Dax. No reason to replace Dax so I think the only way to go about it would be to play Rafa further up as a CAM and see if he can handle it. He can distribute out of the back so maybe it's worth seeing if he could distribute further up.
No matter what, if everyone on this team actually does get healthy at one time, there's going to be a good player sitting on the bench. Whether it's Solli, Cooper, or Le Toux, I don't know.