I will say though, I have played a lot of TCGs and you ALWAYS want the smallest deck allowed. Going over the minimum cap inevitably leads to inefficiency and lower performance, so theres that to consider too.
While this is true for other games, its not really the case in this game.
In this game you don't want the smallest deck allowed.
In this game you can go run around with 1 follower, but that's obviously a terrible idea. I like how there is no minimum number of followers, and how you really Don't need a minimum. If you run around with a very tiny deck, with all the best followers, your deck will either do really well, or it will run out of cards, in which case you die. (soon you might even take dmg each turn for running out of cards)
The Recycle feature (that you can use every turn) also has a huge effect. You can choose to run a bigger deck, and then have the freedom to keep using Recycle every turn, to freely draw for cards that favor you in a certain position. If you play a very tiny deck, you can't go discarding many cards, for fear that you will run out.
You can have as many copies of 1 card as you want. You can run as many copies of Power Cards as you want. Therefore you are not really "watering down your deck" when you have a decently large deck, because its just many copies of the same very powerful cards.