Because a lot of people are well read, unlike the people at Bungie responsible for naming enemies xD Female spell/magic casters/weavers/users are called sorceress or witches in all other iterations of magic or science fiction storytelling. Like here, OP, I'll throw you a bone. Say Bungie puts goats in the game, like you can see them in patrols and such. But then their name plate says, and the grimoire says they are called ducks. Does that make them ducks or goats?