Getting All WF Group Admins from Workfront

Does anyone have a better way to pull all group admins than pulling all the groups and including userGroups:isOwner? I'm trying to compile a list of all the group admins, but so far that's the only way I've found, and the issue I have with that is it gives me all the users in the group instead of just the owners. I'm hoping there's a better way and I'm just not seeing it.

Thanks.