I believe NationBuilder would benefit from a "Manage Lists" permission that allowed managing of all lists.
Right now, our high level volunteers (who are not admins) cannot see/edit lists created by other high level volunteers, because to share it with them would stop the data entry volunteers from being able to actually use the list.
This happens because lists can only be shared with a single permission set (which I believe is also a problem but has been labelled as "not planned" to address).
This is something we are considering but does not have a timeline at the moment.
There are other suggestions on updates to permission sets including sharing by tags. If something is marked 'not planned' and there isn't a reaaaaally solid reason in the official response why we're not doing it then it's still probably an option and you are more than welcome to add your voice there as well.