Because each potato is (kind of) an abject buff to the character you're playing it on, maybe make a blank class that gets the potato buffs and a standard card pool so that they aren't necessarily making the runs easier.

Sometimes you have to choose between 2 brotato that you both don't want. At this moment you can cancel the brotato selection and start without a brotato. Would maybe be better if you couldn't cancel once you activated the well rounded brotato