Ronaldo ultimately plays ST differently to Cavani & Martial.
Its obvious who the better striker is (Ronaldo) - but anyone who has followed Cavani or Martial know that they are support strikers that are able to bring others in to play through hold up play and passing rather than being traditional tap in strikers.
Last season our main attacking threat was for our wider players Rashford and Greewood to score with cavani/martial linking up play or scoring aswell. The main passes came from Bruno to support a whole wide attacking 3.
This season our main attacking threat turned centrally to Ronaldo. Everyone created for Ronaldo including our wider players. Sancho is an example. Rashford turned to RW that had to cross and create for Ronaldo. Greenwood messed up. Even recently Bruno is being played out wide to create for a central striker.
This season we switched how we play from having a wide attack that tried to get in behind off Bruno's creativity to Bruno,Sancho, Rashford and others trying to create for our main central striker in Ronaldo.
He is not a problem due to his productivity, but what he did was change how the team play through the course of a season.
People will probably say - but look how we played without Ronaldo, when cavani and bruno were playing as our ST and False 9. It just doesnt work for me, you dont spend a whole season practicsing team tactics towards getting the best out of a centralised striker like Ronaldo, only for you to drop him and expect False 9's in an unbalanced uncohesive team to play like Messi.
This is why he turned in to a problem for me, albeit a productive one. He changed the way we as a team played from Last Season to this season ultimately because our main attacking tactic changed with his arrival.