I don't understand what are you trying to explain, but it is not Community League. It is UEFA Champions League, this is the highest football competition in the world. No team has a guarantee to win UCL trophy, including Bayern Munich. In the quarter-final, Bayern Munich will face Arsenal, it shouldn't be easy for Bayern Munich to beat Arsenal. If you look at the EPL standings, you must be aware that Arsenal is strong enough to challenge Bayern Munich.
Indeed, in the Champions League there is no guarantee that a team will win the trophy, but to become champions you can look at the squad and team mentality and my prediction this season falls on Real Madrid.
My feeling is that in Arsenal's match against Bayern Munich, Arsenal can qualify for the semifinals. Don't underestimate Bayern Munich in the UCL, but so far Arsenal is a better team this season than Bayern Munich. It's true that the domestic league is not a reference, but for me it will still have a bit of an influence.
Apart from that, Arsenal is more consistent than Bayern Munich and also the mentality of Arteta's team is very scary this season, it is proven that they have never lost against Man City and Liverpool in the league. Lastly, Bayern Munich's record against Arsenal in the knockout phase cannot be the only reflection because Arsenal is 4-5x stronger than their squad in 2017 and Bayern Munich has been left behind by players like Lewandowski, Robben, Thiago, Ribery, Kroos, Schweinsteiger .