This is a very raw idea: Would it be possible (and viable) to have both the benefits of playing solo (only 1 card revealed during questing) and 2 players (decks synergy, setup, wider card pool, etc) "without" the drawbacks?
Specifically I'm thinking in the next idea: Two decks, one of them is just for helping the other to setup faster, and then this second decks "kills" itself, hence leaving the rest of the game in solo-mode. The second deck is meant to be the first player in the 1st round, needs to (help to) setup the main deck, and then commit suicide before questing phase. Only three heroes have the ability to kill themselves for no reason: Tactics Boromir, Caldara, and Treebeard. There is no need to run the three of them; some of you may think Treebeard alone is enough, since it gives access to secrecy and Lore (card draw and scrying).
The main drawback is that many scenarios put more cards during setup due to 2 players mode. This is where the main question of viability surges again.
I've been lazy and I don't have a specific deck in mind for this support-suicidal deck idea. I'm guessing stuff like Deep Knowledge, A Good Harvest+Steward of Gondor, Scrying cards, Gondorian Fire, Blood of Numenor, etc. should work...
EDIT: Forgot that once a deck dies, it takes away all its cards, so this support deck should be consisting mostly of events (and attachments/allies that can work during the very small window they're around.... A Good Harvest+Steward of Gondor could still work, but just for one round)
Edited by Rajam