I think he would be a more natural replacement for Matic going forward than either McTominay or Fred. I also think he has a much higher ceiling than McTominay, although I do rate McSauce especially for big games.
With Matic becoming more of a bit-part player and Pogba likely off in the summer, I think bringing in someone like Rice to our midfield would add a level of calm and consistency that it's going to be lacking, assuming players continue on their current trajectories/leave. Although I did think the same of Schneiderlin to be fair.
But Rice is comfortably better defensively than anyone we have currently, and our CBs have proven on numerous occasions that they could use the protection. He's also good cover for them as, again, we know how hard it is for the likes of Bailly an Lindelof to string together injury-free runs. Assuming it doesn't break the bank, he'd a be a solid addition and could help the likes of Van de Beek/Pogba replacement settle.