Currently we have no way to determine which authz serve the user at the webadmin users and permissions tab.
By legacy, the user names were once set to user@domain, but this was just method of display.
Best if we display the authz name explicitly and store user name without suffixes within the database, as it is duplication.
I set this for 3.6 for now, but maybe we can do this for 3.5.
also namespace will provide hint of where object belong to.
there is authz provider and namespace column in user tab, permissions sub tab, and system permissions dialog
oVirt 3.5 has been released and should include the fix for this issue.