It is all about not underestimating their opponents in this round. Bayern, Manchester City and Real Madrid are the favorites in all those games, but there have been surprises in the past. I would be no exception if one of them gets under pressure, but since it is two games to go, I doubt that any of these teams would falter. I rather expect a few superior games by those teams and then we will see what the next round brings regarding the drawing.
We expects our favorite team to come our victorious in every match played but it's quite important these clubs doesn't fall out of track. UEFA Champions League is definitely not a competition for mediocre teams, the title race is only among the best clubs. We have watch and observe the outstanding performance exhibited by these teams, none of them holds back because striving for good results have always been the ultimate goal. You're correct, these elite clubs are opportune to be on the lists because they've become one of the very tough clubs, proven themselves.
UCL was a competition for best of the best from any european leagues. This competition for the best clubs from any leagues, but there are a few clubs that were fully dominating the competition. It means that if any clubs that was competing in this league must be ready for that.
Any club who was able dominating the competition is always having the best squad in the world. Even real madrid has been winning this competition three times in a row and it was also creating a new record that can't be broken by other club.
The elite clubs have a lot of resources to keep strengthening their club and financial has become the main problem that create the gap between the big and small club.
The big club is always having a very good squad that has been filled by so many great players.