I tend to believe that the mature doe is the very one you want to harvest most. Actually, it is probably advantageous to harvest every mature doe you can. Remember, the mother doe is the catalyst for young buck dispersal as she frequently drives the yearling buck from her home range. Alpha does also dominate bucks for much of the year, so they tend to get the best nutrition. That's why removing does leaves more & better quality food for bucks, along with helping to balance the sex ratios. I think you would see even better results that you have already seen if you would shoot the heck out of the does.