It would be impossible to prove that an accountability must be done by a specific role. Accountabilities could always be done by a new or different role. We have Required Roles but we do not have the ability to dictate what accountabilities the roles have outside of proposing valid governance tensions or valid governance objections. To find a new role filler does not have to mean that you have to add staff. A role can be filled by 30 seconds a week if the role filler deems that 30 seconds is enough to fill the accountabilities to their satisfaction. If no role fillers volunteer and all partners reject the assignment of the role then the role would be filled by the Lead Link because "The Lead Link also holds all un-delegated Circle-level Domains and Accountabilities."