Yep, they would have to be real - but you wouldn't be forced to use alterations. I'm not 100% sure how I would assign Sapir Disks but they might be random. If you get something you don't like, let's say "Cure", but you'd rather have "Curse" - you have a way to get there or maybe you have "Flame" but you think "Flare" would be more helpful.