It is already 1-2 for Bayern Munchen and no matter if Arsenal is the better team the fact that they are down means that they have not been able to convert their many chances,I am also watching this game as I was expecting a whole lot more for Arsenal,it looks difficult now for them to be able to strike back especially considering how much difficulties they had against Porto.Sure the fact that Bayern got the advantage will make the game even more interesting to watch yet I have a lot of doubts as I said regarding the capability of Arsenal of turning things around,I hope they do but things just do not look right at this moment for them,maybe in the break their coach can motivate them further to fight back for real.
Even though Arsenal is in first place in the English league standings, that doesn't mean the opponents they face are easy. Of course, Bayern Munich is a strong team, even though there have been several previous matches that ended in disappointment for Bayern Munich, such as against Deidenhein and Dortmund. Even so, Arsenal cannot underestimate this club, because Bayern Munich is the club that is in first place and also in Group A. In my opinion, this is a hot match, because they are both top-ranked teams which can be said to be like kings against kings.
Even though they are behind, there is a possibility that they can turn things around, as you said, with their coach giving motivation to all of their teammates to be able to turn things around, but they also have to see what kind of opponent they are facing because of course Bayern Munich cannot be underestimated easily.