That was the basic idea for it yeah.
Although, thinking about it now, I'm not sure how well cards that the AI would play would work with this. And the Duplicate and remove options essentially already do this, with nice trade-offs for picking either one.
I think chance modifier cards would only really work if the player had their own set of cards that only affected the AI's cards. Which I think could be a possible exploration in the game. So then maybe some of the players cards could be like : "Give an AI card a higher chance of being picked", "Give 1 AI card a higher chance of being picked, and 1 a lower chance.", "Swap the pick chances on two AI cards". Then duplication would also duplicate a cards chance.
I'm thinking the visuals for this would be that when you increase a cards chance it gets a + symbol on it, and - symbol for decreasing, and then maybe when you pass over to the AI, it shows all the cards base % of being pulled, then adjusts them for the +'s, and -'s.
Then you could also have more player cards like: "Prevent one AI card from being picked this turn.", "Pick an AI card, if the AI plays this card this turn, it will be played twice."
Just rough ideas, since an addition like this would increase complexity a lot, which may not be wanted. But I think there are lots of ideas for more cards through having player specific cards.