I dont see it is illegal ... actually his formation is quite balanced in my viewpoint regardless of top 11 programmers consider it.

he's playing with 2 middle defenders making his team pretty secure.

The 2 defense mid centers on the right and left wings are playing the role of DL and DR if the arrows are set to behind/back.

you can buy dml and dmr and put them in dl and dr positions .. it works try it