Should a shell belonging to one template be able to be updated by from a push from another template?

If there are multiple shell templates on a particular shell level say Project, should a shell belonging to Project template 1 get updated by a push from Project template 2?

The behavior that is observed in our environments allows for all shells (at the same level) to be selected when updating the setup or groups. If all shells get selected then a particular setup or group gets added to all shells regardless of whether or not they are on the same template.

Is this by design?

Thanks,

Michael