He's hardly fit to be anything, let alone a king.
The midget must be blind, if this is who he's chosen. Alibaba is average everywhere, in looks and height and strength, with scarcely enough magoi to support one djinn, let alone the seven that far greater man possess. Judal revels in laughing at them both, in knowing they are so much, much weaker, and in knowing that his understanding of power will bring him far greater conquest than they could ever imagine.
"You're useless," Judal likes telling him, likes watching the way Alibaba's face twists because there's a shred of thought inside of him that really, honestly believes it. "Look at yourself next to Sinbad, next to my Kouen—look how pathetic you are in comparison."
It's like kicking a dog when it's already rolled onto the floor, belly up, but Judal likes it all the same, because it solidifies what he already knows: Alibaba is weak, Aladdin's ideas of what makes a king entirely wrong, and his own choices are right, everything he does is right, and no one can convince him otherwise.