HA/Scaling: Combine PgBouncer/Consul with other role on same node?

Hi everyone,

I’m looking into turning our single-node omnibus installation into a high available installation and thereby also scaling it. I use on-premise virtual machines at three locations.

Now for full high availability the minimal solution is the reference architecture described for 3k users:

However, I was wondering whether it would make sense to combine the PgBouncer and Consul server roles with the application or database roles to just save on the total number of virtual machines?

Does someone have any thoughts on that?