[Eomer of the Rohirrim]

You can speak about the prophecy of Glorfindel all you want. It doesn't take away from the fact that anyone would have killed the Witch King with the Blade of Westernesse. The fact that it was a Hobbit and a Woman who got the job done just made for a nice story.

Yes, the Witch King stood silent for a moment when he discovered Dernhelm's true identity, but this matters not. Had, say, Aragorn stabbed him with a Blade of Westernesse on Weathertop, we would have got the same result.