There are also differences in squad quality. Borussia Dortmund has a stronger squad. Lille has a more modest squad. When this is the case, Borussia Dortmund is automatically the favorite. The team that will probably win the matches and advance to the next round will be the German team. They have been doing well recently and their performances have been on the rise. I think they will continue this rise with Lille.
I think that Dortmund as the finalists of the last Champions League are in any case considered favorites in these matches with Lille, especially since Kovac has changed the team for the better and at least they are quite capable of beating Lille and reaching the quarterfinals. Lille is too inconsistent and their defense is playing much worse now, they can lose to a weaker opponent in Ligue 1, so despite the fact that Dortmund is not having the best season in the Bundesliga, I think they are capable of beating Lille.
At least, Lille has quite an impressive record this season in the Champions League, because previously Lille managed to beat Real Madrid and Atletico too. Thus, Lille is not a completely weak team, because Lille can also play very well and can provide surprises even though they are playing away. Although indeed, in the last few matches, Dortmund has also managed to rise with good match results too.
But even so, the competition in the Champions League will still be a tough competition and match even though they are playing against Lille. If Dortmund loses focus in this match, then of course the results will be bad or maybe not optimal like a draw. If you bet based on the odds, then of course it is enough to choose Dortmund which is basically favored based on the odds available too.