The WitchKing and Gothmog

[Thingol]

That's pretty much the way I see it also Keeper, yet there is very little textual evidence to support it. Personally I think Tolkien did not put much detail into the power and rank of monster's and people so that the reader can make his/her own vision of Middle Earth in their mind.

"I said once that the world he charts was there long before him, and I still believe it. He is a great enough magician to tap our most common nightmares, daydreams, and twilight fancies, but he never invented them either: he found them a place to live, a green alternative to each day's madness here in a poisoned world."

Peter S. Beagle

I love that quote and think it is very handy to keep in mind when reading Tolkien.