I completed stitching together the dirt piles and ditches to the ground mesh. Along the way, I learned how to minimize the artifacts due to poles in the topology.
In general, poles are no problem if the mesh is not smoothed or there is no deformation associated with a vertex that is connected to the pole. The solution is to surround any deforming mesh like a ditch or pile with an edge loop that is at ground level. Then the vertices comprising the loop can be connected via poles without causing any artifacts in shading.
My next task is to deform the grid to conform to the overall topology of the land. I may also work on improving the smoothness of the dirt piles around the Lunette.