Hi Matt,
The "Name" portion of any Customer/Lead/Vendor must be unique, There is good reason for this however. All of these entities are ultimately syncing to a 'Master' table named Entity. The Entity table defines who is a Vendor or a Lead/Customer by specific flags unique to a that type of Entity. Ultimately this means that every Entity in Method (And QuickBooks) must have a uniquely identifying Name. That Being said, The Company Name, First and Last name and Contact fields Do Not need to be Unique, and you can fairly closely mirror the details of your vendor using these fields.
Thanks Matt.
Regards,
Ben