I earn a Great Admiral, only he arrives in a harbor that's locked in by ice. So then I want to move the Admiral to another city with a harbor, right? Except to do that I have to first move him into my city center — but I can't because the city tile is not immediately beside the harbor tile. Why is it that when moving a Great Admiral, you can go to a different harbor, but you cannot transfer him from a harbor? Does that make any sense?