Digging into this a bit more... The "Sync federation" action can be used to sync the following settings:
Hosts
Host sets
LDAP
NTP
SNMP
Syslogs
Users
Virtual Domain
Virtual Domain set
The best part is that the arrays don't have to be zoned correctly for the sync operation to work. They just need to be in the same federation. So don't worry about the state of the federation. Just put the arrays in a federation, perform the sync, and then delete the federation.
Since the building blocks are already in place, we'll see what we can do to make this easier to do in a future SSMC version. For example, select one or more hosts in the Hosts view and have a copy action to another array. Same goes for the other objects above and probably one in Systems to cover SNMP, NTP, LDAP, and syslog.