If you're feeling like your encounter deck smashes you into pieces, you can somewhat ease things for you if you follow this though I got here.

The thing is you can regulate the level of "challenge" it offers if you divide the encounter deck into two parts: moderate and hard. And the game will look like it starts with less pressure on you, but it eventually will grow.

Let me make an example for you using the encounter deck of very first quest - the Passage through Mirkwood.

This deck consists of:

(Goblin Symbol):

1xChieftan Ufthank

2xDol Guldur Beastmaster

3xDol Guldur Orcs

2xNecromancer's Pass

2xEnchanted Stream

3xThe Necromancer's Reach

1xDriven by Shadow

(Tree Symbol):

1xEast Bight Patrol

4xForest Spider(3x actually, because of setup)

1xBlack Forest Bats

2xForest Gate

2xOld Forest Road(1x actually, because of setup)

(Spider Symbol):

1xUngoliant's Spawn

1xHummerhorns

2xKing Spider

2xGreat Forest Web

3xMountains of Mirkwood

1xEyes of the Forest

2xCaught in the Web

What we do now is create Moderate and Hard parts of the deck.

For this one I include in Hard part of the deck:

Ungoliant's Spawn, Hummerhorns, Chief Ufthank, Dol Guldur Beastmaster(1), King Spider(1), Forest Spider(1), Dol Guldur Orc(1), Great Forest Web(1), Enchanted Stream(1), Necromancer's Pass(1), Eyes of the Forest, The Necromancer's Reach(2).

For Moderate part of the deck I put it:

Forest Spider(1), Black Forest Bats, Dol Guldur Orcs(1), East Bight Patrol, Old Forest Road(1), Forest Gate(1), Mountains of Mirkwood(2), Driven by Shadow, Caught in a Web(1).

Now, after I created two parts of the deck, I have some cards left. Those are "libmo" cards. I shuffle them and divide into two even(as close to even as possible) parts, not looking on them, and then randomly add one of the parts to moderate part, and the second one to the hard part of the deck. Then I shuffle both moderate and hard parts, and place finally putting them together(moderate part above the hard) to create an encounter deck for the quest.

With this done, I'm sure I won't be stomped by Ungoliant's spawn on my first turn and overwhelmed by necromancer's reaches too, decreasing the overall difficulty, but deck is still random and I still can't be sure whats waiting for me at the next corner. Same can be done for any quest.

Or how about this?

Take all of the time you invested to analyze the encounter deck, divide them, and figure out an easy vs. medium/hard tier.

Reinvest that time to invest in analyzing the player deck/cards, build the deck and figure out a hero/card combination which is effective.

Then you will defeat the quest even if Ungoliant's spawn appears on turn 1…and you will be well equipped to handle the remainder of the quests without all the stress and worry of evaluating the encounter cards.

I'm a happy only-core-set owner, so no much space for deckbuilding.

And even with this core set, I won with spawn popping out on first turn. This is not the matter of better deck strategy. This is matter of getting comparedly easy start with harder finish.