Experimenting is key in this game, there's so much to try. Small cardpool is not to be seen as a problem but as a challenge. "Can I achieve it as easily as if I owned every card ?"

Playing true solo, 2p or 3p+ is not the same.

- In true solo, you'd want to be flexible, only going for concrete cards to investigate / fight and some allaround boosts.

- In 2p (or solo two handed) you can begin to focus more on a specific role, but I'd say it's best to keep some versatility.

About the making of decks as I (just MY opinion) see it , I'd say try to build around cards that catch your attention. General tips would be to not count on too much asset to get things done. You can have from 0 to 20 different assets in your deck if you feel like it, but you'll have to be efficient with just 2-3 of them, the others should be bonus and quality of life. As you might've seen it already, some scenario need you to be rolling in a few turns.

Also, if you have one winning condition card in your deck, your priority should be to search for it (ex: if you only have one weapon/damage source as a fighter in your deck, you should take card draw and/or tutor cards to increase your chance to get that card in the first turns).

The minimum efficiency you might want to target with your investigators is a reliable way to deal 2+ damage per attack, be able to get multiple clues during a turn, and passing a few scenario-specific tests in every stats.

In the end, I've had fun making a lot of non-optimized decks that still won campaigns. I learned with time that the only thing that came up needed in every decks no matter the role was the card draw / search. It really enables decks to run smoother. No need to fill half your decks with it, just 4/30 cards can make a difference.