I can see Prince Taldaram maybe working in a combo decks. I don't know why would you put it, but ok. Sure. MAYBE(that a big maybe), it will work out, somehow. Probably.
Have you ever seen a combo deck that revolves around faceless manipulator copying a minion like malygos or prophet velen and bursting you down with spells? That's why you would put it in. In that deck it would serve the same purpose as faceless at a lower cost (with a drawback of course). Considering it has happened before I don't think it is as unlikely as you think.
What about the old Warlock combo of using Leroy with power overwlming and a faceless manipulator you can now do it