If a tile represents a 100 x 100 mile section, then each tile should be treated similar to a city. I think tiles should contain their own subsections which would show the tile's makeup. Then one tile would not necessarily be one terrain type. Terrain could then be drawn more realistically and the land used more efficiently. Look at mainland Britain. That little island is home to numerous mines, factories, farms, hills, rivers, etc. Yet compare the land to the Earth maps in Civ2. You can't build an Empire using those ten squares of land. But in its prime, the British Empire controlled most of the world. From North America to the South Pacific to India.