I'd like to also to pitch the idea of the brothers varying in ferocity, for the lack of a better word. For example, considering Inigo turns into a wolf, one could try to calm him like one would a dog, or, of one were to become to vicious, they could lock them up in the dungeon. Heck, I'd even assume Topias has learned some sort of trick to calming the brothers after working with them for so long.