Shapes of horses are almost defined. The length of legs and face were the key but I probably don't have to come back and change them later any more. The tanker might still need some more adjustments but it shouldn't be a big deal as long as horses are right.
I started toning the body of the black horse. To see the color/value contrast, I made the dried grass lighter. The value or color value of the tanker might be tricky because one house is dark but the other one is light.