We were never good with Tosun this season. Performances got much better when Calvert-Lewin and then Richarlison took his spot. Tosun's not the answer to anything.
Saw a run of nice performances and results when Silva first went to this midfield, then everyone worked out how to play against it, now it's not very good. The only things he's tried are shuffling the attackers and adding a defender, neither of which does anything to address the problem.
The options are there but he has to try them. Gana-Gomes-Sigurdsson is broken.