I don't think you need so many copies of
CbtR. 2 might be enough because you need to play
Gollum, PD only once. After that he'll be coming on his own. Or, you could keep the 4 copies of
CbtR and switch
Plotting Deceiver for
Vile Creature. He could also win some skirmishes. Also, instead of one
Black Numenorean, I'd take one
Corsair Marauder. Simply as a bonus card which might discard a nasty possession or 2 (such as
Aragorn's Bow).
Mumak Chieftain on
Mumakil will win skirmishes often, but not often enough, I think.
Durin III will almost always win in that fight and many others might cause you trouble. You need some pumps or something else that will raise your strength. I'd suggest
Field of the Fallen and
Seasoned Leader combo, but that's a different deck altogether.
All in all, I like the idea very much and you're experienced enough deckbuilder to see through gameplay what your deck needs. I believe you'll find that you need more strength, but we'll see.