Culturally linked starts has nothing to do with your actual location on the map. Instead, it controls who your neighbors are. For example, the Americans will always spawn near the Iroquois and the Aztecs if they're in the game, the French will always be near the Germans, English, and Russians, etc.
If you want correct starting locations, there are a few places where you can find scenarios that place civs in their correct territories on a world map. I am not really that interested in the whole "play on the earth map" thing, so I'm not positive where you need to go to get this, only that it's possible.