The headcount owner can add headcount users as headcount administrators.
Headcount administrators can view all the rows in the Headcount Input tab (not just the rows to which they have been assigned in the workflow).
The key reason for having a headcount administrator is to ensure that someone in your organization (other than the headcount owner) has full access to the Headcount Input tab. In the event of the headcount owner losing their password and getting locked out of the tab, the administrator can unlock the tab and retrieve the headcount data.
In addition to the above safeguard, the headcount administrator can:
Import, add and adjust headcount data.
Add headcount users (and administrators).
Assign users to rows in the headcount workflow (the baseline remains assigned to the headcount owner).