To start with, this deck focuses on Beregond being your primary defender, and Théoden being your primary attacker. I included Éowyn because she both provides the needed tactics resources for the deck, and can function as a last resort attacker if Théoden isn't enough. Éowyn is otherwise going to be your primary hero for questing, with Théoden's buffing her .
The idea is for making sure the heroes survive and, should something happen to Beregond due to an unforeseen Shadow effect (Looking at you, Hummerhorns) or something along the lines of an Umbar Assassin, Prince Imrahil can jump in and fill the void for a good portion of your tricks in this deck. Once Théoden has Snowmane, he can be questing with Éowyn for a respectable amount. Herugrim will be boosting his to a very respectable 6. Golden Shield can go on Théoden if you need a secondary blocker in the first turn should you draw Dúnedain Hunter and not have Defender of Rammas. Raven-winged Helm goes on Beregond, and Honour Guard is used to protect from either Archery effects or from When Revealed effects that damage your questing characters. In my experience, this means Éowyn primarily. Windfola goes on Éowyn to make sure she stays questing when a revealed effect forces you to remove questing Heroes or characters from the quest, as her being removed will likely mean you fail the quest. Envoy of Pelargir is great for providing some resource smoothing if it's needed, as well as helping quest. Unexpected Courage goes on Beregond if you're not drawing the cards you need to ready him for multiple defenses or Théoden if you are so that you can attack multiple times.
Now for some of the more odd parts of this deck that I personally don't see very often. Steward of Orthanc is placed here in order to provide some card draw, and help with questing. With Beregond and The Galadhrim's Greeting, threat shouldn't be an issue unless you're playing with a friend who doesn't have threat management. As a rule of thumb, I always check with them before using Steward's ability to make sure I'm not harming them more than helping us as a whole with the card draw. Now for the off-sphere cards included in this deck, consisting of Daughter of the Nimrodel and Steward of Gondor. Without A Good Harvest, you will not be able to play these. If you're playing solo, then these are best used for [Steward of Gondor](/card/01026. If you're playing with a friend or Two-Handed, then it would likely be best to let them use their own SoG for their own purposes and instead use your Harvests for Daughter of the Nimrodel to heal either your Heroes or their Heroes. Another excellent use of a Harvest is to make sure you have access to Hour of Wrath when you might need it, such as in the case of an unfortunate number of surges that bring out creatures you need to defend against or to use with Éowyn's action to clear the board of creatures that have engaged you. Oath of Eorl is for dealing with something that you don't want to attack at all due to a forced effect of some kind; a couple of Nazgul encounters come to mind. Tides of Fate is particularly useful in encounters where you have enemies frequently buffed by Shadow effects. Haradrim from the Against the Shadow cycle immediately come to mind, allowing you to save Sterner than Steel and Hasty Stroke for more important Shadow effects that deal direct damage.