How to configure AME First Responder Wins with a Position Approval Hierarchy

I have configured a Position Approval Hierarchy with 3 Positions: Buyer, Reviewer, and Approver consisting of multiple Employees per Position.

The PO Approval Process runs successfully with the Position Approval Hierarchy except Approval is limited to one Employee per Position.

Is there a way to utilize the AME First Responder Wins Voting Method to allow for all Employees within a Position to receive the Approval Notification?

I've tried configuring the Purchase Order Approval Transaction Type using AME as follows without success:

1) Created Approver Group with Voting Method = First Responder Wins and Group Member = HR Positions: Reviewer

2) Created approval-group chain of authority Action Type with Ordering Mode = Parallel and Voting Method = First Responder Wins