While it is possible that Wanda was always a Faq unit, can't the ruler of a city choose which kind of caster gets popped? If so, does Faq really seem like a place which would pop a croakamancer? Of course, Banhammer didn't exactly get what he was hoping for in an heir, so perfect control is out of the question, but isn't this the unit type we're talking about - i.e. are all casters the same "type" as far as production orders are concerned?