Psh, just because one guy didn't like the idea of an "Artificially Created Humanoid" doesn't mean that it's a bad idea. And for a "Guild" of mages, they didn't seem to cooperate with each other much. It's not like "Mass Production" is a modern concept. If a hundred smiths can get together to make a thousand swords, why couldn't a hundred mages come together to make a thousand mana potions? It was less of a guild and more of a mercenary outfit. Besides, it's not like Tyrael would do something like this if he didn't get authorization: I plan to have Lucilia popped by later and tell him off for revealing a darker side of the college, but Tyrael was never really one to keep such matters a secret. It's like sausage: if you really like them, you should at least know how to make them.