Kids should get a special class on this topic in civics. I always felt fortunate that in my school we had a lot of effort put in by several teachers on this general topic. Only as an adult did I appreciate how important it is for kids to question the labels put on by people trying to trick.
Certain Kings/statesmen earned the title of " GREAT " in the past. Alexander the Great Peter the Great Catherine the Great etc. Most of them cost a lot of lives. So not so applicable to today's kids.
Who do you ask your kids to appreciate and copy ? A footballer ? Scientist ? etc. Or a blood thirsty tyrant.