I think this is a humorous idea with a lot of potential for parody! The RPG roles of warrior, wizard and tank have been used for years and years, so reversing the roles is fun, even if the wizard essentially plays like how a warrior would anyways. I liked the kamikaze healer and the angry AOE tank, though. I'd like to see what other weird ideas could come from this line of thinking--like a pegasus knight whose armor is too heavy for their steed to carry.