I must have tried to defeat this quest 20 times before I finally did it. The real triumph was that I did it with only 4 Dwarves in my deck - Bofur and three Veteran Axe Hands. Originally, I tried about 15 times with leadership/tactics comprised of Boromir (HoN), Prince Imrahil, and Beregond. I really wanted a full Gondor-themed deck. But, the truth is I could not find a way to use Prince Imrahil enough to be worth his threat level, and I was having severe threat problems by stage 4 every time I made it there. The solution ended up being the addition of spirit Glorfindel (FoS). Not only did he come in at 6 threat less than Imrahil, he also provided me the much-needed threat reduction, when revealed cancel effects, and shadow cancel effects. I also brought with him Light of Valinor x3, Unexpected Courage x3, Ancient Mathom x1, Elrond's Council x3, Imladris Stargazer x1, Arwen Undomial x1, and Bofur x1.
The other good thing about grabbing a spirit hero, was that it forced me to reconstruct my deck. It's not that I had a bad deck, but there are soo many cool cards that sometimes it gets really hard to eliminate them. Since I was running a tri-sphere deck, I knew I couldn't keep some of the higher cost cards for fear of not acquiring enough resources. There is only about ~7% chance of drawing Steward of Gondor during initial draw, so you can't rely on that.
Even after I taliored my deck, I found myself taking cards out that didn't serve me in the game. If I drew a card and it didn't fit an immediate need, I discarded it permanently. This is what it took to defeat this quest. It took me six tries with Boromir, Beregond, and Glorfindel. Let me say that this was, by far, the hardest quest I have ever attempted.
I would gladly post my player deck and strategy (as best as I can remember) later, if anyone is interested. I did not use much of my player deck, as I was able to defeat the quest in six rounds with a final score of 95. I probably only drew about 16 total cards, and had about 4-5 in my hand upon completion.