SB knows far more about personnel and formations then we'll ever know so this post is made with that in mind.
A lot of teams play 4-2-3-1
You need good attacking full backs to provide width, which we have - Elmo and Robertson.
Hudd and Livermore can play the 2 holding roles (defensive cover)
Three attacking midfielders of Diame central and then 2 out of Brady/Hernandez/Aluko/Ramirez even Sagbo.
Jelavic up front but not isolated because the 3 attacking midfielders should be able to support much quicker.
A lot of teams play 4-2-3-1
You need good attacking full backs to provide width, which we have - Elmo and Robertson.
Hudd and Livermore can play the 2 holding roles (defensive cover)
Three attacking midfielders of Diame central and then 2 out of Brady/Hernandez/Aluko/Ramirez even Sagbo.
Jelavic up front but not isolated because the 3 attacking midfielders should be able to support much quicker.