The Mass Leader
The One and Only
I just realized something that may be new to a lot of people: The barbarians can be very useful when you make a scenario!
I just used a huge horde of barbarians to put some balance in a scenario: I builded 3 empires that were almost power-equal, but I left their cities in the center of the map without any army, and a lot of barbarians there. Just as the game begins, the barbarians take all those towns and it throws the 3 nations on a rush to retake those cities.
I also used barbarians to populate American continent on a Colonization-like scenario. The european empires were builded with the standard nations. Then, i builded many french cities in America, and gave them to barbarians to take (in a single turn, they took all of them). Done. The europeans had no mercy when they arrived there and I could hide the Americas map from them. It simulated better the great navigations.
I also used barbarians on a game about the Rags Revolution in Brazil (1835-1845). There was the Brazilian Empire Army, the Independent Republic of South's Revolutionary Army, the Latin Neighbor Nations army, and a bunch of barbarian troops with 2 cities (taken from the other players). The barbarians were there to simulate the bandit brigades that wandered in southern Brazil by that time.
If anyone is going to make a scenario, try using barbarians to make a weak nation that does not negotiates with the others and does not enters any alliance. Or just to leave some cities to be takes by the player and AI during the game.