Due to docker crashing my server, I went with a different strategy. I abandoned bridging totally for docker for my 2nd,3rd nics.
Nic 1 (2.5G Host): Plex, Tautulli
Nic 2(port A): Binhex/DelugeVPN)
Nic 3(port b): Bridge br2 - VMs
I haven't had a single crash since.