The idea here is to crush everything. Start by getting a couple allies in play, using one or more of the following:
Then, use as many A Very Good Tale as possible. Build up huge piles of huge allies. Use Vilya any time you like, because the only cards in this deck costing less than 3 are the Beorning Skin-changers and 8 of the events. (And any of those events is worth playing at almost any time.) The best time to use Vilya though is either right before or right after committing to the quest, because you might get a random The Free Peoples or Sneak Attack.
Other random combos: With Elrond gaining spirit, play Elrond's Counsels. Use Vigilant Guard to save Glóin if he takes too much damage. Use Gamling to recycle Háma and/or Grimbold. Súlien or Faramir can do double-duty with Spare Hood and Cloak, as can any blocker or attacker, or hey Gildor Inglorion. Treebeard gets free healing from Wellinghall Preserver. Etcetera.
Here's the list of allies who do not share a trait with Prince Imrahil. Point being, I want to keep this list short, although not too short, because...
All the cards I cut are still in the sideboard. Ranger of Cardolan theoretically helps get started on A Very Good Tale, but the timing is limited so I axed it. Priorities: Beorn is so good I want more, but 2 is probably enough. All other uniques are not important enough to justify 2x. For non-uniques: Giant Bear and Beorning Skin-changer get 3 because of course they do, Soldier of Erebor has a self-readying effect, and Knight of the White Tower has quest power. Veteran of Nanduhirion gets shorted because it's not quite as good, and Wellinghall Preserver gets shorted because it's lower cost and not as good for A Very Good Tale. The Free Peoples is good for a random Vilya target, and better than the other events that I cut.