I have different view over this. I meant Brest is at the top, but they often fought against the weak teams. It's kinda different when they are gonna face Real Madrid. This pretty much the same situation like when Real Madrid fought Atalanta.
Real Madrid at the midtable, and Atalanta was topping the competition by winning all of ez games, yet they able to destroy Atalanta.
What's the difference then?
In my opinion, the difference lies in the team, Real Madrid has a roster of players worth 10 while Atalanta's roster of players reaches 1 if it goes well, also in terms of expenses and wages.
Obviously the performances will be different, obviously. But that's not a given, football isn't established so the weakest team can beat the strongest team.
On paper, Real Madrid are clearly the better team from all angles but in a match there will be results that may differ from any prediction. Thus, although Real Madrid is the team that will certainly be favored to win, but Real Madrid will also not get an easy victory. When Real Madrid played away against Atalanta, the score was 2-3, and it really shows that the seeded team cannot always win easily. However, considering that is the Champions League where Real Madrid are the best team, then of course Real Madrid will always have a very good chance of beating Brest and advancing to the next round, no doubt I guess.