great job with the painting and the conversions! the one thing that seems the be lacking with the unit is a sense of fullness. when i think of a unit of skeletons i think of a limitless horde. the models that are partially or completely in the ground are cool but they make the unit look patchy as a whole.
in conclusion: excellent job and the unit looks great for something like a diorama but i prefer my unit blocks to have a more solid look to them.