This (like a sharded Raft group) is somewhat correct :P.

If you can sacrifice consistency (causal instead of external), you can get EPaxos. If you can sacrifice more, you can get Single Paxos. Both of them can increase concurrency to some degree, and can improve availability over a leader based RSM system like Muti-paxos or Raft.

I believe there are other ways to make the trade-off, even making the trade-off dynamically. Hopefully, I can talk about it more soon.

I work on etcd/raft, which is a shared Raft implementation by TiDB(TiKV), Cockroachdb, etcd and many more.