We watched the same brick performances over the last 18th months with them in the side. What makes you think it will be any different when they return?
Maddison provides good passing and creativity in/from the middle of the pitch - we would look a much more balanced side with him in Simons position in this 4231. Solanke can hold the ball up and is a focal point which is two of the main things lacking in Richarlison.
It wouldn't turn us in to world beaters but would certainly improve us in the areas we are currently finding most frustrating.