Merge dock items from all workgroups

I like how I can add an MCX setting for a group that populates its users' docks with some applications, and I like that it will merge it with whatever else they happen to have in their docks already. But if a user belongs to more than one group, it will ask them at login to choose one group, and only that group's applications get added. I would like it to merge all of the applications from all of the groups. Is this possible?