It's in picture #3, the lead horse, I can't tell if the right front leg is bent the wrong way, or if it's supposed to be in a kind of trot. Like I said, it may be my dodgy eyes and there's really nothing wrong at all. But if not, at least you can catch it before too much more work has gone on.
as for suggestions (if you didn't think of it:rolleyes maybe you could give the grass and bushes some different shades of green?, and some more different heights of the long grass. But knowing your building skills you have already thought of that, well I am sure that you did
It really does have a life-like quality to the step now. The leg doesn't look like it's folding the wrong way and when set against the rest of the scene, it looks like it's about to break into a run. Lookin' good over here!