Barcelona has appointed Thiago Alcantara as Hansi Flick's assistant, his presence among the Barcelona coaching staff will make it easier for the players to adapt to the strategies used by Hansi Flick because they are no longer hampered by the language factor. Hansi Flick is a great coach and Barcelona on average has great players, it is not difficult for the two of them to understand each other.
Maybe in his first season he will experience a few difficulties, but he will overcome them based on the experience he had with the previous team. Hansi Flick and Guardiola are different types of coaches, but Barcelona will not throw away its identity, which always applies the Tiki Taka playing style even though it is led by someone from outside Barcelona.
Flik is very different from Guardiola, and of course he will build a team in his own way. The coaching headquarters is also very important for working with the team, alone Flik will not oto cover everyone, and even more so when you mentioned the language barrier, this is also a very important point that you need to take into account. Flik is a good coach, he worked with the best of the best, so I think that he should be no worse than Xavi. Xavi achieved good results despite his little experience and a short career, so Flik should be definitely no worse, and perhaps even better than him.