and they got no way to verify what happening with jellal, or any other would-be adversary.
(frieza did always have the tendency of killing his own men...)

they could even keep him alive through the whole plan, and kill him only when they actually kill all the magic in the world.


EDIT:
notice how the cover character page says "don't underestimate chubby people"? in the same chapter that shows the fatso being an idiot and getting screwed over?