I feel like De Zerbi is not the type of manager that will change the shape of a whole team, like do not expect some Xabi type of "how did this happen" style of results, that is not going to happen. I think the best that they can hope for would be just getting a good result with whatever they have, based on what they were expected, nothing much.
There are teams who do terrible compared to what is expected of them, so they should be happy if they do enough to be where they are expected, which would be top four at the best case. Meaning, if they finish fourth then they should be happy. Will this work or happen and like see the end of the season? I do not know, but I know that they are not going to be all that great at all.
Xabi luck with Leverkusen in the Bundesliga is considered difficult to achieve, although it is not impossible to happen. De Zerbi leaving Brighton, for me this still has a big question mark, especially when choosing Marseille as his destination. Previously, De Zerbi was widely linked with Bayern, United and Chelsea, and there were expectations he could replace Pep Guardiola at the Etihad one day.
Meanwhile, De Zerbi was given the task of bringing Marsielle to a top four finish in the standings, where this season they ended in 8th place in the standings, outside the European zone. Maybe winning another domestic trophy, apart from Ligue 1, is a target to achieve like the French Super Cup. In terms of experience, De Zerbi can certainly lead Marseille to the Champions League zone next season, provided he gets adequate budget support to build squad depth.