I think he should be allowed to focus on the transitional and creative side of his game. So I think he should either be played alongside an energetic destroyer (Amrabat, maybe Casemiro if he can get some legs back) or perhaps
behind a 'Kante type hound' as you put it (again, probably also Amrabat?), ready to step in, sweep up the loose ball and create with it.
I think I prefer the former option because the whole value of players like Mainoo is that they don't need to sit behind the play and receive the ball in deep safe spaces. He has a picture in his head even when he's in the middle of things, and he is fine receiving the ball in more contested spaces.
So:
GK
FB CB CB FB
Mainoo Amrabat
Bruno