I support this idea, which not only affects the 12 nymphs, but the other 15 rare cards too.
For example: Your favorite deck is a pharoah/flying discord deck, and you want to use it in the tourney. Unfortunately, you only have 5 pharoahs/discords and you upgraded them all. Now you are forced to use a deck that you don't like as much as your pharoah deck or your flying discord deck, and you lose in the first round.
I could make almost 30 other situations like that.
This seems like it would be easy to code, but I don't yet have any experience in coding so correct me if I'm wrong.