Hi CK,
Overall looks good, like it. Agree with Pen that there would be little standing, except tents, Quonsets, PSP etc etc.
Re-colour, it depends what type of soil it is. That looks like sandy soil, and if so then pretty good.
You're never going to get sharp ground texs, but maybe try some darker earth colours (freshly dug), instead of that light sandy one, that may mask some of the blocky-ness?
Cheers
Shessi