The compartmentalized consensus separates follower as acceptor and replica, and divorces command-log replication from data replication. It also seems to use two acceptors group as in horizontal scaling.
The compartmentalized consensus does not have relay nodes that do relay/aggregation. The idea in PigPaxos is simply that using randomized relay/aggregators have surprising power for vertically scaling Paxos.
The bipartisan Paxos, seems to apply the compartmentalized consensus idea to EPaxos.