I mean, being wizard King sounds like both a mental and physical job. While Asta is fairly intelligent, I don't really see him having the kinda mind a wizard King needs.

I mean i think Wizard King is different than say Naruto's Hokage as the wizard King is legit just the military leader and Julius did not seem to have tons of paperwork. I mean he was running around a lot, the kingdom did not fall and he does not seem tired. Plus, I don't believe we've seen him do tons of paper work.

However even with something like that out of the way, Asta just does not seem to be the type who is the leader of men. At least not to me. An inspiration sure, but a leader?

Edit : OK... I retract what I said about the paperwork