I played through a game myself with this deck. And even though I'm not the greatest player and did things like forget to include the three Gandalfs (I added them halfway through the game, but still got stinted for another few turns regardless), and played Steward of Gondor on Eowyn instead of Beravor, the deck did well. It seems to be the case that having the three spheres involved condensed into one player leads to a more efficient game, since you don't get the extra staging draws from another player. It's the magic draws from Beravor that make a multi-sphered deck like this work.
For deck construction with only one core set, three-sphere decks seem to be the way to go, even if they're rather tricky. You will almost always need incredible draw to pull it off, but that's what Lore is for.
(If people are interested in the full, detailed game log, including unheeded prayers for Gandalf, it's on my blog.)
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