Barcelona players currently only need a coach who is able to guide them in a better direction because there are many great players in Barcelona currently. However, all their greatness will be meaningless if their abilities are used in the wrong position by their own coach, so we all need to see how Barcelona's new coach manages every player who is already in the Barcelona squad next season when they want to compete with any rival, including with Real Madrid. Because Barcelona needs to find a more effective solution by not complaining more about their own financial condition.
Flick got a very good team, he doesn’t need to start over, put something together piece by piece to get a result, he already has a good team after Xavi, so it will be easier for him to start, but the final result will depend on the strategy he will use, and the decisions which he will take during the game. He also has experience managing large teams, so he can achieve good results, he has almost everything necessary for this. And if he holds out well in the first season, then he will be able to get the opportunity for new transfers.
However, in my opinion, the role of management is also very important to determine whether a coach's strategy will work or not, because coaches must also get full support from management to carry out what they want to implement, including the players' needs according to their wishes. And at the moment, I don't think Barcelona is able to fulfill all the needs that the coach wants. Things like this can also sometimes be an obstacle for coaches.
The composition of players they have can be said to be the composition of players that should be enough to enable them to compete, but in the end it depends on whether they can be utilized well or not. The reason is that previously they had a player composition that was not much different, but they still failed, especially when Koeman was leading the Barcelona squad. This is still a question for me, because we haven't seen how far Flick can bring good changes to Barcelona.