Atletico Madrid was just lucky, all the teams they met are weak teams except PSG and Barcelona, in the next few weeks they will meet Bayer Leverkusen, this match Atletico Madrid might lose. I would give more chance Leverkusen to win because they have better squad, while Atletico Madrid is only depend on Griezmann all the day.
I don't think so, from the performance they showed in Laliga, I think they stand chance over this teams, just that If they repeat what they did to Barcelona in Laliga to other teams In Champions league then they should be preapare to loose the particular game ,not really the performance but the style they used could land them in conceding goals( if not that Barcelona were wasteful,the outcome resultcould have been different aswell. UCL is no play ground I know, let's see what will happen in their next game but imo I think they should win Leverkusen from what have been watching so far...
But in my opinion in the match against Leverkusen, Diego Simeone will use a different strategy because of course he will adjust every opponent he faces and in my opinion what is feared will not happen. Because what I know so far is that Atletico Madrid's defense is very tight, especially their goalkeeper who was very good when facing Barcelona in La Liga. Moreover, this match will be played in front of their own supporters, it will be an extra strength in this match.
In addition, Atletico Madrid's current appearance is very epic, they even have a great chance of winning La Liga, although the Champions League is impossible because there are still Liverpool, Arsenal, and Real Madrid who are still favorites to win the UCL. However, when competing against Leverkusen this will be a turning point for them, I think Diego Simeone will give his best to get points because this victory is very important for them to be able to qualify directly for the last 16 to avoid entering the play-off round. By the way, if Atletico wins the UCL, then it will be their first UCL trophy.