Is there a way to create a catchall rule for procurement approvals?

Has anyone created a catchall approval rule for Procurement related approvals (requisitions, purchase orders, change orders)? We have lots of rules and some of them have users hardcoded into them. While org changes are fairly rare, they do happen. We wanted to be able to create a "catchall approval group" where approvals would route in the event that no "rule" is triggered.

Does anyone know if this is possible and, if so, could you share how you accomplished it?