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.
I'd even pick Real Madrid and Manchester City over Bayern Munich. Bayern Munich have no much quality in midfied, if they take that performance used in the Champions League group stage and Bundesliga against some certain clubs, then I can assure you that they'll lose. They have a good defense, winger's and attackers but not a strong and creative midfielder's.
They still remain top favorites alongside, Real Madrid, Manchester City, Inter Milan and Bayern Munich. I'm listing Inter Milan because, they got to qualify and went on to reach the Champions League finals last season. They played well defended well with all they've got. It was just a superb finishing from Rodri that decided the how the game ended.