All those noSQL or newSQL have more than one leader per table they have a distinct leader for each partition.
So if you have 6 server and 2 partition you could have 3 servers for partition number #1 and 3 different servers for partition number #2.
If you want extra performance you could make the server simply store key->value mapping using quorum write like Cassandra is doing but to keep data consistency you still have 2 choice
#1 use Optimistic concurrency (an app performing an update will verify if the data has changed since the app last read that data).
#2 using some kind of Lease, elect one machine to be the only one allowed to write to that partition for some time period.
Option #1 do not give faster transaction throughput but could offer lower tail latency.
Option #2 bring you back to square one of having a leader so you better just use (Paxos/Raf)
So if you have 6 server and 2 partition you could have 3 servers for partition number #1 and 3 different servers for partition number #2.
If you want extra performance you could make the server simply store key->value mapping using quorum write like Cassandra is doing but to keep data consistency you still have 2 choice
#1 use Optimistic concurrency (an app performing an update will verify if the data has changed since the app last read that data).
#2 using some kind of Lease, elect one machine to be the only one allowed to write to that partition for some time period.
Option #1 do not give faster transaction throughput but could offer lower tail latency.
Option #2 bring you back to square one of having a leader so you better just use (Paxos/Raf)