Leyzer,
if your kids can’t just fight with each other without external help, you are doing something wrong!
Find online questions about Purim and print it with one kid so that he can ask others and then give them prizes. Make some questions simple, and others open-ended, so that a couple of kids could disagree and make it into a discussion. See YWNCR as an example!
Ask everyone to prepare a story and 3 questions after that. Everyone votes on best story. Again, prizes.