Madrid this season is not in the best condition and form in both La Liga and UCL, so indeed we cannot say that Salzburg will be an easy opponent for them, although so far Salzburg has also shown poor performance and consistency in the UCL, but they will certainly come with high spirits to give resistance or at least aim for a draw at the Santiago Bernabeu later.
Regarding Brest, although they may benefit from weaker opponents in recent matches, Madrid still need to focus and not take it lightly, because after all they have shown great consistency to be in the top 7 at the moment.
Trust me that Real Madrid can provide answers to the concerns of many people in the Champions League this season.
The two other teams that Real Madrid will face will not make Real Madrid lose points.
The same as you that this is not about the team that Real Madrid will face being weak, but it concerns the greatness of Real Madrid.
In the last few seasons in the Champions League, Real Madrid's situation has been in a position that has made many people think that Real Madrid will lose momentum, but it turns out that this is not the case because the Champions League is a big stage.