Requisition Approval Aggregation Reassignments

We have created our requisition approvals to use two tasks for Header Hierarchy with Header Stage. We have set the aggregation so if the cost centre manager in the first task is the same as the line manager in the second task then they get a single notification to approve both tasks.

However, if the manager is away, we are having to reassign each task separately. Is this standard functionality or can we reassign the aggregation for both tasks to a single person one time?

Thank you