Yes, fierce helps a lot, you need the 4 Uruk Fighters / 4 Uruk Warriors, and 4 Slayers as well (too good to pass up). You can drop the swords in favor of only skirmish events (and Saruman's Ambitions, those are great), makes it so you "get" them more. You can probably drop Scout, Shaman, Rager, Brood and Savages, and add in
Saruman, Servant of the Eye and the uruks that cost -2 when Saruman is out (
Uruk Ravager, I think).
Evil Afoot works wonders with
Worry builds.
Demands of the Sackville-Bagginses can go. I'd switch
Spies of Saruman for
Saruman's Snows and/or
Wariness (get some surprise kills) If you want to dip into rares,
Greed might also be good to have 1-2,
Troop of Uruk-hai is better than Raiding-Party, one more
Orthanc Assassin could be good as well, and, of course,
Savagery to Match Their Numbers is the most important card.
Saruman, Keeper of Isengard also throws quite a wrench at Free Peoples, and if most decks are using Aragorn (as most should),
Can You Protect Me From Yourself is great.
Beyond the Height of Men could be bumped up to 2.
OrthanC Berserker is another great addition, as is a singleton Palantir. A second Captain could be great too, though your mileage may vary.