Apply Buyer Assignment rules to item sourced from an agreement?

Summary:

If an item is sourced from an agreement (BPA), the buyer listed on the source agreement override the buyer assignment rule and requisition is created based on buyer in source agreement.

Is there any additional configuration to apply buyer assignment rule in this scenario?

Content (required):

In my client organization, all agreements (CPA and BPA) is owned by group of individuals. Hence buyer on the agreements is setup as one of buyer from the group.

Additionally, they have tactical buyers managing the day-to-day activities of the requisitions and purchase orders. These buyers are organized based on department cost center.