They are genetic anomalies, and from what I have read they are less likely to survive predators anyways due to their odd coloring making it more difficult for them to stay hidden. It also seems to me, that if all hunters pass them over we could end up in a situation where we get increasing numbers of piebald/albino animals and decreasing numbers of deer with normal coloration. So for that reason I would shoot the piebald/albino over the normal animal even if the piebald/albino were smaller.