You might be right. As a manager, Tuchel is able to improve a team rather than focusing on one player. Everyone at Chelsea plays for him. The performance of Koulibaly will be excellent. The Serie A matches are less intense and revolve more around tactics than the Premier League, so it is possible for Koulibaly to adapt quite quickly to the fast-paced nature of the Premier League. As with Koulibaly, Raheem Sterling from City is also a nice addition, and his addition will have a big impact on Chelsea.
Chelsea have a good squad, Coulibaly is a great reinforcement. We'll see how Sterling fits into the team, but Chelsea have good strikers to score goals without him. At the end of the season, there was a decline in the team, but that's normal, they just finished the season, and now after a good rest, I think that we can expect a good game from Chelsea. Tuchel is a good and very demanding coach, he knows how to work with the players, I don’t know if they will be able to fight on equal terms with City and Liverpool all season, but I would really like that.
The transfer market this summer is something that is very crucial for Chelsea to return to being challengers for the title. Tuchel seems very satisfied with their latest signings, namely Koulibaly and Sterling, both of which are considered to be suitable for his Chelsea style of play.
Chelsea are quite late in entering the transfer market this summer because they have to clear up the club's internal problems first. However, obviously can not be satisfied with the current squad. And I'm sure that Chelsea's shopping is not over. They would use the remaining time to hunt for the right players.