Moreover, if the four teams you mentioned above do not face each other in the knockout rounds, I would also like to say that the teams that will enter the semifinals will be Real Madrid, Inter Milan, Bayern Muchen and Man City. Next, the Real Madrid vs Man City team will enter the final.
However, in my opinion, Man City will become champions again, just imagine when the team is losing its pillar players and there is a storm of injuries but Man City's game is still dangerous for every opponent. This is just my prediction.
I prefer Real Madrid and Bayern Munich to advance to the final if they don't meet in the knock-out round because it will be a big match that is quite evenly matched. Man City is still the favorite to advance to the semifinals but I am not so sure they can reach the final with their performance in several previous match results in the domestic league. The ideal semi-final composition could feature four strong teams, namely Man City, Real Madrid, Inter Milan and Bayern Munich, everyone hopes that this scenario can work so that the Champions League semifinals will be more interesting and competitive.
The strength of Real Madrid and Bayern Munich has far more potential this season to advance to the final round compared to Man City because these two teams have almost even quality players in all positions. If you look at the goals conceded in the domestic league, these two teams are still quite stable so the defense also looks very strong in supporting them to advance to the semifinals and finals this season in the Champions League.
Real Madrid had some failures as well. They tied their home game against Rayo Vallecano, they also tied their game against a weak Sevilla team that couldn't win a game in ages and they lost the game against Atletico Madrid, which is not a big deal but still. Manchester City is one game behind Real Madrid if you compare the domestic leagues and if they win it they are about equal with Real Madrid. It is just 1 point. But in regards to Manchester City I think I understand what you mean. They are not the same as last season, but still very good and more importantly, good enough to beat any other team in the Champions League. But yes Bayern could be an interesting team for the final besides some others of course.