Ndidi is a good PL midfielder when played to his strengths in a system that suits him.
He will never be a 10, he is a destroyer, and he needs someone to sit alongside him that can a) support him defensively and b) create.
Anyone that is forced to play along Soumare all season will look gash, doubly so if they are coached by a no-hoper that hasn't got a clue how to setup a team.