I like how the map reflects two "eras" concurrently -- pre and post colonization.  

As I play through it, two strategies occur to me:  Either evenly spacing all features around the map and attempting to protect each one individually, or concentrating all the features in one area to limit losses to two.

I don't think this is the intended way to interact with the game, perhaps these "optimal" paths could be removed by randomizing the placement of the cultural landmarks.