This deck should be airbrushed on the side of a van. It's just wizards and giant eagles swooping in and out of play laying waste to everything in sight. It feels like something a high school rock band would write a concept album about when they're not playing D&D.
The idea is to maximize Gwaihir's Debt and Sneak Attack targeting Core Gandalf and using Wizard Pipe to reset the combo. Depending on draw and the situation, however, there are other valid targets for both (namely Meneldor and Descendant of Thorondor).
Éowyn and Radagast handle questing, Denethor with Gondorian Shield and Armored Destrier handle defense (Radagast can do some defending too thanks to his Response), and the eagles and itinerant wizard mostly handle combat (with Eowyn around to bring down a boss). Radagast's Staff and Steward of Gondor provide plenty of resources. I put Steward on Radagast because there are fewer cards in the deck he can't pay for compared to Eowyn, and the Gondor trait makes him a good target for the other shield. Daeron's Runes, The Eagles Are Coming!, and Word of Command make digging for your combo pieces go somewhat quickly. Messenger Raven is helpful when you have used your last Sneak Attack or Gwaihir's Debt from hand and get the ally back at the end of the phase/round. At this point, I will speculatively use the pipe to put the ally back and hope to get the Gwaihir's Debt. If you don't get it the Raven can draw the ally back for you so you still get to see a new card during the next Resource phase.
I've only played this one-handed solo, but it seems the obvious partner for this deck is a heavy-questing deck with cancellation. This deck does alright with questing at the start thanks to Eowyn, but most allies that you bring in to play are combat-focused and you can find yourself losing to location-lock. You are also at the mercy of any and all treacheries and shadow effects. I wouldn't feel great playing this in a larger multiplayer game due to the focus on combat without much in the way of Sentinel and Ranged characters. Other than those weaknesses, cards/effects I would look at adding are Protector of Lórien because you can start to get a lot of duplicate uniques, A Burning Brand for Radagast to help with shadow effects, hero-readying, and possibly some healing. I just don't know if I'd want to remove anything from the list for those, however, due to risk of watering-down the reliability of the deck doing what it does best.
I would call this a fun, somewhat-casual deck that can hold it's own against even more difficult quests provided they are enemy-focused.