Yes, I have records on all four of them. Looking at Llaynasa's, it's true that she was sold to me directly by the debt collector who enslaved her. With that in mind, it seems highly unlikely she could have been planted or recruited by a Hlaalu agent since I bought her.

Included with every slave is a record of all of their past transactions, indicating things like location, cost and notes on their skills and service record. It can affect their market price and often factors into how they're treated or what role they're purchased to fulfill. I know them pretty well from my time at the Vivec Arena. Though I never figured I'd be on the other end of one.