How should I say it, dunno if we could get our enemy's cards or not since I haven't finished my 1st playthrough yet, but the game is nothing but horrible at card game building.
First thing is about decks. Enemies get a fully functional deck and we do not. Well, there's a way around it. In the college tutorial, go to the far right and you can farm cards infinitely there. You can also get 5 relics that increases your deck limit by 1 for a total of 5 if you run that place 5 times. If you don't farm there for about 10-15 times, of course you'd feel overwhelmed. That place, if you go repeatedly and save scum in the boss room, you can choose the card you want and stack up your deck until you feel safe and proceed to the main story.
2nd thing is card balancing. Devs probably think it's a good idea to give some enemies stupidly op decks (remember the bugs at 1st map?). Dunno if we could get them but in the card gallery I see a card with 3 mana cost yet deals 30 damage. Yeah. 30 damage.
3rd is hand sizes. Unless they let us change our max hand from 4 to 10 cards, I generally see almost no good strats that could be formulated on this hand. Also about hands, Devs really need to balance out the cost of enemies's cards. For almost the same effect, The shitty corpse can force us to discard our whole deck for a "measly" cost of 5 while ours took 8 in exchange for dealing damage equal to discard. Not really that useful unless you build a deck that forces enemies to hold more than 20 cards at once. And just so you know, this is among the rare cards in the fighter card branch.
4th is demon cards. Fyi, it's not actually worthless in a run where you want to keep the bar low. Just remember to use only when against a boss since otherwise, it would stack up so fast. Still have no idea how many demon cards there are, but i've seen 3: one effectively allows a flatout reset, cost 40 corruption, one deals a flat 20 damage, cost 50(not sure) corruption, and one deals the number of cards in grave x3 damage, cost 60 corruption. There are also loactions to reduce corruption but each only reduce 20 so don't put too much hope in it. It's either the bathroom encounter or the faithful room at 1st floor so yea...just don't put too much hope here.
At the end of the day, all you could do is to either try to build up your deck at the very first few turns or kill them as soon as possible. One is the job of the DoT card that sets a barrier to deal 3 damage per turn. It's dang useful against enemies that try to spam your deck with debuffs. Since max card draw is 4, spend about 2 slots to set up barrier cards and 2 more cards to fill the blank slots. Even better if at least one of those cards can add cards or debuff into your deck each turn. Watch as you enemy is helpless against some paper cut damage and bleed to death. Another way is to really try the normal card draw way. Still uses the same principle to either beat your foe to death fast enough or slot in enough card draw and card restore to some how ignore enemies's mechanics. There are two cards called Bathe fresh air" and "Endure the fear" and they kinda works the same as Multislash and Will of the city in a singleton deck in LoR, though you kind of need a ton of them... And they're also rare as heck.
Also, forgive me if I'm wrong at anything, since I'm too exhausted to play this game after the 1st floor...