Standard PO Approval hierarchy migration to PO AME

We are implementing PO AME for our client, currently they are using Standard Position Hierarchy for PO Approval.

In production instance,  100 no.of POs are in In-progress status.

Client requirement is after implementation of PO AME, Can we have all these In-Progress in same status and approval level.

Client is not interested to reset workflow and initiate again approval through PO AME.

Please suggest feasible solution for this requirement.

Thanks,

Praveen