Caprina Springs said:

i think the lack of a solid outline in some areas of the horse for a highlight is what youre missing. especially the orange one. theres no reflected backlight from the bright sun. i like where you were going with the soft light around the silhouette of the horse but it seems to just cover it. what setting do you have that specific layer with the soft light?

EDIT

i also just noticed this; the bg upstages the horse because of how sharp the image is, try a light blur on them

Angels angels said:

The only issues I see are very small details.

The legs on the black horse look a bit undefined and almost swollen, and its feet are a bit more blury than the rest of the horse. It also is missing some definition in some areas, such as the back legs kind of blend into a black mass. You could try using some very light white to define the shape a bit more.

The orange one looks very good, except for the front leg and foot is a bit sharp and blocky. It also could use some of the highlights for definition as well. Also the face/muzzle looks a bit big for the horse's face, and the ears are a bit blury and could use some definition.

I hope this isn't to harsh. Like I said just being very nit picky if thats what you are looking for! lol :) They look amazing though!