I thought this morning that Uldor could still have Thorn killed. If Thorn comes to Lachrandir, it's not absolutely out of the question that he could be caught by one of Brodda's or Uldor's henchmen. Then he could be brought to Uldor, as Uldor wished earlier, and from there, things would progress quickly and end, undoubtedly, in Thorn's termination.
Can we do that? Thuringwethil can have Lachrandir (presumabely, she doesn't know about Thorn), and Uldor, suspecting Thorn from when he first contacted Khandir, can deal with that old man.