Five hogs plus a lvl 7 Bk if you get in trouble will most likely get the wiz twr, as long as there is nothing really nasty hidden by it.
Personally I would just go with three healing spells and not worry about taking it out, but I am not the great loon pooh bah. Five lvl 6 loons in your castle would be a nice complement. They are much tougher then lvl 5.
