If Manchester City, Real Madrid and Bayern Munich are the top three clubs in the Champions League, then I think one more club should be added here and that is Arsenal. Maybe we don't see such a good performance from Arsenal in the Champions League, that's why we can't put this team in the list of favorite teams.
If you add Arsenal to the list, you will have to consider to add more clubs to it. Arsenal is good but not like a very strong team with too much better competitiveness than many clubs around Europe. Arsenal are not much better than Barcelona and if you bring this question up for discussion, there will not come to any universal conclusion. It means these clubs are not different too much in quality and competitiveness.
Injury problems are unwelcome and can happen to every club, but Arsenal's players are known to have the most injuries every season.
Injury issue was most commonly in era of Arsene Wenger and several previous years. It seems that in last two seasons, injury is no longer biggest problem in Arsenal and it helps them to play impressive in Premier League and Champions League.
It is not right to add Bayern Munich to the list of favorite teams even though Bayern Munich has a good achievement in the Bundesliga but still, Bayern Munich also does not have a big achievement in the Champions League. Thus, I think it is not right if you judge Bayern Munich as the favorite team to win the Champions League trophy. Because after all, in the Champions League basically only Real Madrid always has a good chance to get the trophy every season. Because at least, other teams that have a chance to be able to play in the final match also at least depend on the situation in the same season too.
After all, even though other teams managed to qualify for the Champions League final match but in reality, they still find it difficult to win in the final match if the opponent they face is Real Madrid. Therefore, I personally believe that at least only Real Madrid has a good chance, even though there is also Manchester City but still, that Real Madrid also has better quality than other teams.