No one doubts that Andre Onana is a good goalkeeper. His career shows it. But what worries me is that the Manchester United defense makes very simple mistakes. Andre Onana can react harshly to simple mistakes made by the defense. After all, someone has to react that way anyway. You cannot expect high performance from your goalkeeper when the defender makes too many mistakes.
Yes, he has proven his work as a very excellent goalkeeper at Inter Milan in the previous season. He is said to be able to provide a better performance at the club compared to the previous goalkeeper de Gea. But indeed the path will not be that easy, especially as you say if Man United's back line is not that good. So he will definitely need great efforts to always keep the goal from conceding goals. yes, at least it won't be as heavy as before when de Gea because there was always Maguire who became controversial. 