The first leg has already given a picture of how the second leg will be because we shouldn't expect any comeback from Real Madrid even if they will win Arsenal but the goals won't reach 3 and even if it does, Arsenal will also score one or two goals so the chances of a comeback is not possible for Real Madrid. I think the reason why Arsenal couldn't win their Premier League match today was because they were preparing ahead of the second leg hence they didn't even care about the match against Brentford. Arsenal is a difficult team for Real Madrid and even in their head to head. No matter how strong a team is, there are teams they meet and find it difficult to have an easy win and it appears like Arsenal is one of the teams that Real Madrid finds uneasy.
Arsenal definitely has to really prepare their squad so that they stay fit and in good shape overall, both physically and mentally. because they have to visit Real Madrid's headquarters, which of course will have a different atmosphere compared to playing at home. And the draw in yesterday's match against Brentford was not a big problem. because the important thing is that Arsenal doesn't lose points completely. And in this match, Arteta also rotated a little and divided playing time more evenly to maintain the stamina of the main players. And Saka also wasn't played from the start. So it is clear that Arteta is preparing to face Real Madrid.
About whether it is possible for Real Madrid to turn things around in the second leg. So the answer is not very easy. Maybe Real Madrid can win, but yes, I agree it will be very difficult to achieve an aggregate of 3 goals. Because of course Arsenal will also try to score goals.