It is true that Chelsea did have some difficulty scoring enough goals to win the game. As far as I am concerned, that problem will not be going to give panic anymore.
It is unlikely that he will be a game-changing player for Chelsea in the near future. But other than that he will be there to give Chelsea a more stable performance in the attacking lineup.
I think Aubameyang still has got his touch and pace right but I would agree on that he wouldn't make much of an impact signing but I also might be wrong. We saw how well he was at Barca if he can continue that same thing then I think he will be the most goalscorer for Chelsea this season but well let's see about that as it depends mostly on Tuchel and his plans.