You are right that there should be no reason for Arsenal not to be able to win this match when Bayern Munich's condition is unstable, Arsenal should be able to take advantage of this opportunity to beat Bayern Munich and advance to the semifinals. Arsenal must remember that their previous meeting resulted in Arsenal being eliminated in the UCL and Arsenal having to avenge that defeat by beating Bayern Munich. The opportunity will not come twice for Arsenal because they have been beaten by Bayern Munich for years and they finally meet again.
So, on this occasion, Arsenal is in very good condition, they are competing with the top teams in the title race, which means that Arsenal is very strong this season and they have prepared for Arsenal's meeting in the big match against Munich. If Arsenal is able to beat Munich, it will be a very proud achievement. for the English team because Arsenal and Man City are the favorite teams in the UCL.
Arsenal who will welcome Bayern Munich at home in quite prime condition after they managed to be unbeaten in 7 matches in all competitions, while Bayern Munich actually came with quite bad capital after they lost the opportunity to continue to press Leverkusen in the domestic league, yes Bayern Munich came with 5 wins and 2 consecutive defeats in the league, The contrast between Arsenal and Bayern Munich is of course obvious, and it is fitting that many of us here see if Arsenal will be able to beat Bayern Munich later in the first leg, but isn't the opposite also possible, it is not impossible if Bayern Munich actually makes Arsenal as an outlet for their revenge for defeat in the league later?
I think even though the two teams are in opposite performances, but I will not try to underestimate Bayern Munich in that game, like a lion injured they will be more dangerous at the moment, I think Arteta should not underestimate Bayern Munich even though Arsenal have upper hand now because after all Bayern Munich can give surprises that Arsenal cannot imagine later even though they play at Emirates Stadium.