cool idea, but it wouldn't work with the maps we have now.
i don't think it's so much of a 3d issue, but more with the layout of the land/sea. They don't match or lead in to the other side.
Like mentioned before, the hq's and fields are all laid out in a way to compliment the setup we have now.
If HTC ever made a change the maps would have to be designed with the hq's near or in the middle of a country, with the fields laid out around them.