I like this deck, I actually made a deck like this in a Towers Standard format back in the day that I really liked at the time.... One thing I found was that using only
Feathered and
Blades Drawn exclusively really puts all your eggs in the 'minions being wounded' basket. As mentioned above, Dunland (and Moria in TS) really aren't stopped much by this approach. Not to mention the cases where your opponent may have some archery fodder minions that die and then leave a big one that would only get one exertion from the mount, and the Lorien Swordsmen can die quickly. I found it best to throw in some other Elven skirmish events in case the minions aren't wounded, though I don't recall exactly what else was out there in Towers.
I also found that the deck could clog up the hand a bit, elven swords can help a lot with that as well as pairing with a shadow that flows.
Another thing mentioned above was that starting
Eowyn, Lady of Rohan would be a good call - she can prevent kills to other companions and she's valiant, which means
Simbelmyne can pull your Eomer or horses easily. And that reminds me - I also found personally that
Eomer, TMoR is the one that benefits the most from those elven archers. He may not get the benefit of
Feathered, but he is still much stronger than a
Lorien Swordsman. A skirmish event you could consider if using more Rohan companions is
An Honorable Charge. Versatile if your fellowship is mixed with elves and Rohan.