Carriers & Fulfillment Settings/Accounts syncing

We have two FedEx accounts and two UPS accounts. When I check services in one FedEx account, the other FedEx account services sync to it (same when I check settings in one of the UPS accounts). This is so frustrating. If the service settings in each account were isolated and unique to a particular account, our shippers could choose a shipping method and not have to fill in the correct account - it could be automatically filled in. Because of this, our shippers have to add one more step to each transaction. It seems so basic to me; I am surprised this has not been resolved or improved upon.