Denethor remains a dedicated defender. Build him up with A Burning Brand, Self Preservation and Dúnedain Warning (from another player) or Protector of Lórien. He is also useful to shuffle away Attercops and predict part of the encounter cards that will come next turn. Song of Wisdom can be used to put the Brand on another non- defender, like Aragorn.
This deck's allies are a bit more competent in terms of combat. The Eagles are always useful, while Mirkwood Runner can really do some damage. I forewent any healing in my allies, as you want them to do combat or quest well or at least be chump blockers. The Daughter of the Nimrodel is too expensive and not good enough for any of those things.
Try to keep Feint for the bigger enemies. The encounter deck is quite large, so it is unpredictable which enemies you'll get, most of the time you can use either Forest Snare or a big attack if you are set up to deal with Attercops, Trolls, or Marsh Adders. Quick Strike helps to swiftly deal with weaker or weakened enemies with Legolas, which also gives some progress.
Strider's Path can help bypass Travel effects, and deal with locations that have a nasty effect while they are active, which allows you to deal with them quickly during the quest phase of the same turn.