There's a duplicate in The Lord of the Rings - J. R. R. Tolkien:

Denethor (LotR - Tolkien)
Denethor II (LotR - Tolkien)

The familiar Denethor who appears in the books (and movies) is technically Denethor II, and I'm certain that's who the Denethor nominator meant. Either name would work, as long as there's only one of him.