Noldor and Silvan shall work together
2 decks made with elves. The Elrond's deck is made to play silvan characters everytime possible, i recommed having "steward" or "O Lorien!" in the first round, if not, taking a mulligan may be the best option because what's cool about this deck are the ally card effects.
The Arwen's deck is basically the "support" thing, made to low the threat of the other player, give him resources in case he needs them and attack the ennemies with haldir while Elrond or Thranduil defend. As both decks have ranged characters other versions with "dunedain signal" may work also pretty well, so the Arwen player could be engaging most of the ennemies while no risking their heros. I've added some "burning brands" to both because i consider it one of the best cards in the game, if Elrond gets it with an "unexpected courage" the game will get a lot easier. This deck works for siege, battle and normal quests. And Galadriel and Galdor will ensure Arwen has always cards to get rid of.
If you get "Mirror of Galadriel" with "Silver Harp" you'll have a lot possibilities to survive most of the quests over there.