Replying to my own post here, I've verified that it's currently not possible to do a greenfield deploy of oVirt 4.4.0 w/ hosted engine on EPYC CPUs due to the system setting a requirement of 'virt-ssbd' for the final HE definition after the move to shared storage. The local HE runs perfectly through the setup process because it correctly uses 'amd-ssbd' but unfortunately that doesn't stick after the disks are moved.

You can work around it via 'virsh -r dumpxml HostedEngine > /tmp/he.xml', then editing that file to simply change 'virt-ssbd' to 'amd-ssbd'. Start it via 'virsh create /tmp/he.xml' and now it runs fine. You can get into the admin interface and if you want to run something hacky could at this point change the cluster CPU type from 'Secure AMD EPYC' to just 'AMD EPYC', take everything down and bring it back up cleanly... hosted engine will now work because the requirement for virt-ssbd (not available on EPYC when using CentOS 8.1 or presumably RHEL 8, amd-ssbd is needed) is gone.