Multiple Sage 300 ERP databases - one “Enterprise” sales manager

We have a client using CRM - they have four Sage 300 ERP databases. Each one of these companies can have the same customer info, exception might be the contact info for the customer. They assign a salesperson in ERP/CRM to the customer but they would like to assign an "Enterprise" sales manager to all of the customers in CRM - almost like a national account scenario. I know this is not possible in CRM but is there a third party product available?