When Sargon overthrew Lugalzagesi and seized power he gained an already united kingdom which he could use to advantage in military campaigns to establish the first empire over all of Mesopotamia. He may have been helped in this by his own legend which established his humble backgrounds.
Yes, it is a good idea. It's even better if you know the most commonly used language of whatever place you are traveling to. Like if you were to travel to France it's a good idea to be fluent in French.
