Yes, his goals and success in Real Madrid was also due to the fact that the club already had some great players who all helped made the team a great team. Their abilities and contributions accelerated Ronaldo’s goal scoring era in the team. No can can deny that he’s a great striker and finisher, but he can’t do it alone. And that’s why he needs the backup of the team.
Manchester United didn’t have the experience in football players at Real Madrid had.
it looks like there is a big difference in the performance and quality of the squads in Madrid and United. that's what makes Ronaldo may be difficult to develop his football technique.
because it was United who was in a bad squad condition when Ronaldo came. United does not have the character of players who can support Ronaldo on the front lines. that's what makes Ronaldo like stuck in making goals last season.
the different qualities of the team may make it difficult for Ronaldo to develop if he uses the same way of playing when he was at Madrid.