A rule of thumb with babies.. "Tops may come, but bottoms NEVER." This means the body may change a LOT.. neck.. but the legs are what they are. If the size of the joints are small and round on a foal.. they will be on the horse. If the hocks are way higher than the knees they will be later.
The most common neglect I see in foals are the feet. Need to keep them trimmed and level to help that baby grow straight.
I won't judge foals.. except by their parents (want to see both if I can) and their siblings if I can lay eyes on them too. Prepotency is a wonderful thing sometimes. Other times? Not so much!!