Prince of Egypt might have been more psychologically compelling if it had set up a rivalry between the good and bad brothers--between Aaron and Ramses--for Moses' soul.
Prince of Egypt might have been more compelling if it had set up a rivalry between Aaron and Ramses for Mose's soul, giving the characters more depth. 
mnli hypothesis: Prince of Egypt might have been more compelling if it had set up a rivalry between Aaron and Ramses for Mose's soul, giving the characters more depth.  premise: Prince of Egypt might have been more psychologically compelling if it had set up a rivalry between the good and bad brothers--between Aaron and Ramses--for Moses' soul.