There is another angle to that, because Casemiro joining means we can FINALLY stop playing guys like Fred and McTominay out of positions. This IMO will turn things massively in our favour. And who knows, maybe, maybe if we put McTominay on the right side of midfield 3 and tell him to keep it simple, we might have an useful player.
Obviously, it is far from ideal, but it puts our midfield in a completely different situation.
This is also why I was against buying De Jong since we can't put around him players who would get the best of him. With Casemiro, it's a different story.