Not exactly correct, Softnum. The starting location (when the settler is placed on map) is passed to a separate function that makes the starting location good. This means that the terrain is modified and new resources added.
Terrain modification can be seen best in tundra / ice starts: your capitol will not have any tundra or ice, that'll be transformed to plains and grassland instead. This sometimes leads to interesting resource placement not seen otherwise: deer is placed only on tundra (fur on tundra and snow), but when they're within the starting area, the tundra (and snow) is transformed to plains. Plains/Forest Deer has unimproved yield of F2P2 - more than any other tile. This is essentially the same as settling on plains hill. But give two plains/forest deers to the capitol, and you have the strongest possible start barring stone/marble on plains hill to settle on.