IMO you should keep your king. Aggressiveness can be.... over come (?). Look at your accident, the regular male did almost the same..... it's their nature. If handled properly, they won't be that vicious. Further, as they get older, they become more calm (though often only a bit).
Try this: Keep him in a sorority... I'm serious! First keep the females floating (preferably 4 and +). Then after a few days - after he had calm down, release them. If he feels no threat, he will be the "referee" between the females. I have often done this and it reduces aggressiveness. Oh be sure to use large enough pumps in the tank to avoid spawning.