Dele is at his best making late runs into space. If he’s playing on the outside of a midfield 3 he can run to space created by the front 3. It’s similar to how the US has put Pulisic in that position and he’s really flourished in it.Dele needs to be further up the pitch. Tactically, he dropped back a lot last season and did a great job at what he was asked to do, but his offensive numbers suffered because of it.
It's better for the team if he's further up in a 4-2-3-1, 3-4-1-2 or 4-4-2 diamond.