so if i understand correctly, when wandering in wild lands, you draw an encounter card, and that card tells you which other cards you need to draw, then you have a circumstance deck which either improves or hurts your players stats?
that’s alot of data for a card game, but i’m not sure if there is an automatic solution to figure out how to remove unnecessary decks. some of your decks could be combined or separated, but i don’t know of any algorithm to solve that other than keeping track of the rarity of a feature or counting how many steps the mechanic takes to complete.
some of the decks are more important and more vague, so alot of your more specific decks might get refactored into those vague decks. for example, maybe the NPC, weather, and situation cards could just be encounter cards, since they are similar in how random they happen.
the loot deck is very different from these random events, as its probably triggered by a victory of some kind, rather than being random. random loot might need to be specific to the encounter though, because more difficult encounters usually offer greater rewards. if you want to make the rewards random, but also tied to the difficulty, maybe you could have a few tiers of loot decks, so tough encounters provide the best loot.
some of your deck descriptions sounded kinda mixed in a way that wastes a variable amount of downtime looking for a compatible card:
maybe you could try separate decks for each terrain to speed up searches, or maybe terrain is decided by the encounter card, instead of the board, so you never get incompatible encounters.
maybe you could separate the circumstance deck into reward and punishment decks, so you don’t have to keep searching through a deck to find a compatible card, or maybe circumstance cards could be encounter cards as well.
any time there is a potential incompatibility, its a sign that those concepts are related and dependent on each other, and maybe those should be part of the same card.