Actually, there is a theory that since Groose wanted to stay on the surface, he is the origin of the gerudo. Due to his eye color, hair color, and the colors he wears (blue + yellow, and his necklace which is green and orange which seem to be connected to Lanayru or desert colors in this and other game), some think he is where the gerudo race originated. I think there was an article about this a while ago.