I'm sure there's an exact answer, and this may not be it, but I would do a couple things prior to sending the PFD.
First, are all 3 reporting balances, or is it just the CA?
Next, I would look at Direct Merchants. If there is no balance, and it is older than your average credit age, then its removal could harm your score, assuming the "Worst Delinquency" box on your FICO report isn't report something like 120+ or 150+ days late. If it is reporting a balance due or if it is new, then I would dispute based on the reason that it is a duplicate account.
HSBC has a right to be there, but I don't think they can report a balance due. Correct me someone if I am wrong. I would send a PFD to HSBC and ask for the removal of all 3 accounts.
Finally, after 2-3 weeks from sending the PFD to HSBC, DV the CA. And wait to see what happens with the OC.