the motivation for this fellowship is to create a deck/fellowship, that can strongly benefit from a guarded attachment. i usually do not like guarded, because the additional enemy/location in the 1. or 2. round can be quite hard to deal with. in addition, the guarded attachment is usually usable 1 or 2 rounds after it was played. furthermore, you need luck to get it early. if you get it late (or not at all) it rarely is game-changing.
so, how to get an guarded early in play and early usable. in addition is there a guarded attachment, that is worth the investment to focus 2 decks on that one attachment?
this is the resolution under the circumstance, that the use of the mariners compass rally frees up a guarded attachment:
the best guarded is Ring of Thrór. it needs a dwarf, but that is not this much of a restriction. i would name the ring of thror as vilya for dwarfs. o.k. you cannot play all cards only attachments, but for that there is no exhausting needed, the opposite, it readies the hero.
so, at least 1 dwarfhero is needed. if the hero has leadership he can have the mariners compass, and location as guarded is save. which ld-dwarfit would be? dain is the choice, because the attachments can only attached to dwarfs there should be more dwarfs in the fellowship. then how to get an enemy killed save 1. round, and select a specific attachement? the choice is Éowyn.
get the ring 1. round she puts into play the ring, dain the compass (contract helps to refresh after that). if the guard is a location, use the compass and free the ring in the travel phase. if the guard is an enemy, kill the enemy with eowyn in the combat phase and free the ring. both ways free the ring 1. round. with that arrangement, a strategy around that attachment can be build and used 1. turn.
if the mariners compass do NOT work like that, after the ring is guarded by a location, dain can choose an Explorer's Almanac and attach it to the guarded location then there is a chance to free up the ring early, but it is not save. would be more likely 2. or 3. round.
to select these 2 attachments you need grey wanderer-decks. so, the ring must be this good,that he can compensate for the 2 selected attachments, which ones could else be e.g. strider and song of kingdom.
dain is kind of obvious, setup with the one ring take inner strength. mulligan for stargazer and make the best of ring. try to get thorongil early and mine your heart out. if the one ring is not usable, put 2 hasty strokes in it.
eowyn should be played as a "normal" grey wanderer-deck. mulligan for timely aid, get song of kingdom early and play as much timely aid as possible as long you are in secrecy. drinking song helps to find them. use sneak attack with gandalf or to make a very good tale. Tome of Atanatar from the other deck helps to re-use timely aid or very good tale. with resourceful and a possible steward (from the daindeck) she can at least play a dwarf every round. don´t mind the much discarding, dain has 2 will of the west, 1 for each. remember she can use 1 not-tactic-card every round played first. so if the song of kings does not come early, she can theoretically play 1 timely aid or good tale every round and play the tactic-card after that.
if this arrangement is playable (or worth it) to lay it with a different guarded attachement, i do not know. show me if you have an idea. what have to be optimized? i am not sure, if the ratio between carddraw(only gandalf(sneak) and drinking song + perhaps deep knowledge from the other deck) and allies is the best in the eowyndeck. in the daindeck i would not like to reduce the attachementrating. if he get king under the mountain early it gets 3 cards per round into play.