Manchester City will be the strongest team if they manage to get Mbappe because the quality that Mbappe has will encourage them to become a team that has goal-hungry front players. However, Manchester City efforts to get Mbappe are certainly not easy because Real Madrid will be at the forefront of getting Mbappe. But everything could change if Mbappe is more interested in playing in the Premier League then Manchester City or Liverpool will be his goal.
It would be great to watch Mbappe at Manchester City. I'm sure every Manchester City fan would want that. But we know that Mbappe had some problems before when he was in the same team with Neymar and Messi. He might have similar problems playing with Haaland. There are younger players at Real Madrid, so he can gain respect from them. And we can see him as a dominant character at Real Madrid. But when he plays with Haaland he might not be the dominant character. I think he will be more successful at Real Madrid.