I think that is why I now prefer the Europa League Group Stages, it's not as cut and dry overall as the Champions League Group Stages.
Manchester United lost twice in last season's Group Stages, Dundalk beat Maccabi Tel-Aviv and only lost 2-1 to Zenit, Roma drew three games, Genk topped their group, Sassuolo finished bottom, Fiorentina lost to PAOK and Southampton and Internazionale failed to qualify from their group.
I think as well you get a more diverse selection of sides than the Champions League, where the same sides seem to qualify year in, year out.