Is there a way to revise which Workflow the Payables Agent workarea/nav button goes to?

Wondering if you take a duplicate of the Payables Agent (or any of the agents in the ERP Agents nav), duplicate it, and customize it. How/is it possible to customize the workflow being accessed when a user clicks that 'button' on the Navigation?

If its not, can we say with some certainty that there are agents that are seeded, and "uneditable" or "uncustomizable" in the nav?

Thanks!