Tchouameni and Kamara look very promising but they both carry the risk of taking time to adapt to the EPL. Because they are young, less experienced and play in a weaker league. Same risks Sancho carried essentially and now we're seeing some of that. Of course there is also the risk they might never turn out as good as we expect. They are riskier transfers than Rice, in my opinion, which is why I put them separately.
Bissouma and Ndidi are currently the two best shielding CDMs in the EPL outside of the big 4 teams (City, United, Liverpool, Chelsea) in my opinion. They have also been doing it consistently for at least 3 years and they would cost less than Rice because they don't have English tax.