Based on your opinion, Real Madrid is not strong teams in Champion League and success become the winner? I don't think true about many top teams loss and left with weakness teams but success qualified until Champion League final round after Dortmund and Real Madrid as the most stronger teams.
For next season, usually team with mentality winning such as Real Madrid has bigger opportunity for winning Champion League and their habit get three consecutive winning after did last several years ago.
The new teams participants such as Bayern Leverkusen or the Europe League winner Atalanta can't guarantee will success in Champion League, although they had impressive performance last season but Champion League has own difficulty since phase group after adopting new format until knock out or semifinal round phase.
They do not have a guarantee to do well, but they are not expected to win it neither anyway. I mean if Atalanta or/and Leverkusen ends up going out of the group stage, which will be a different system for now, but lets assume that they go out of the group stage, that would be more than enough. I think that has to be the most important part, if they end up with teams that they could beat, and they get the results they should, that would be more than what people expect from them anyway.
This is why I believe that the best way to move forward with this would be just realizing that we are going to end up with a good return for them. There is no need to expect them to win the title, that would be expecting way too much from them anyway.