Snow White's prince is named Charming. At the beginning of the song Someday My Prince Will Come Snowhite says "Anyone could see that the prince was Charming"
John Smith is not a prince and Pocahontas did not marry until the second movie where she chose John Rolf over John Smith. Kuzco is an emperor, not a prince and hercules is a demi-god. I rarely see Megara considered a princess so Hercules would not be considered a prince either. We consider Mulan a princess so it's fine to consider Shang a prince even though technically he is a general.