Your conclusion makes sense, but nevertheless every team will try to do their best because there is a prize at stake every game they play. Lens also have good form as a competitor, but of course they don't look like the best contenders in the Champions League because other top teams tend to have strong chances and mentality.
In addition, Lens do not have much experience in the Champions League which means they will return home early after the group stage. But anything can happen, maybe next season will be different even though Lens' chances are very low.
Lens must try to bring in several new players next season and they must be consistent and more focused in Ligue 1 because conditions next season will be much different from this season, where there will be many challengers who will try to play better than before. So that Lens' opportunity to remain consistent and be able to finish in runner up position will be much more difficult, a big challenge for coaches in facing other competitors and an increasingly busy match schedule will also affect the fitness condition of the players.
Realistically Lens's chances are very small because they are not an experienced team and have a mentality in the Champions League. It will be quite difficult for Lens to get past the group stage, especially if you are in a group with a great team with experience in the Champions League. So speaking of quality and experience, it is certain that they will find it difficult to compete so their targets will definitely not be excessive.