Eagles of the Misty Mountains is the driving force of the eagle deck. While overcosted at first, there are so many ways eagles can leave play that these guys will be beasts in a couple turns. Support of the Eagles adds to the madness. So if you have four resources laying around and one of these in hand, you know what to do.

Dawn Take you All is not that good. It's good in theory, paying two resources to cancel up to four shadow effects, but it doesn't really work in practice. There's always the chance that the shadow cards don't have effects, or much more frequent, that more enemies will be engaged with one player than the others. There are just to many other better options.

Dunedain Signal is a very good card. For one resource you can have a defender for the entire table. Of course, many characters that you want to defend already have sentinel, but there will nearly always be one that doesn't. The other cards that grant sentinel are Shadowfax; which only attaches to Gandalf, Elven Mail; which only attaches to Noldor or Silvan; and Arwen; which is where most of the Signal's competition lies. What it comes down to is whether or not you want to pay an extra resource for two willpower. One important note for all sentinel cards is that... sentinel is useless in solo!

This ally with a 5-health Treebeard can make an all-Lore deck decent. Normally, Ents are annoying with their "come into play exhausted" but this one gives you access to its ability already. Trigger Treebeard's ability then you have an automatic target. Wellinghall Preserver's 3 quest stat is already decent and you should be using this ally to do just that. However, if the scenario becomes combat-heavy, they can still take some punches with its 2-defense and 3-health.

Song of Battle is probably the least useful of the sphere-granting attachments. There isn't a particular reason for wanting a Tactics icon in any given deck. Often it's used to get weapons in a low threat, staging area attack deck, but outside of corner cases like that, it's just a generally useful glue card.