Given your numbers:
For sustaining what can be culled annually, no more than two mature bucks and one or two poor yearlings, with no disadvantage if the latter are not taken, any excess of males will be 'managed' by the incumbents; after a three years of this, you may be able to find three mature bucks a year to take, bearing in mind that it will take a minimum of two years for a mature buck culled from their respective territories to be replaced adequately by his successor.
Cull 50% of all females annually, if you can; if you feel you have overdone the doe cull, all will revert to mean within one ensuing season's slight easing of same, but generally the overdoing of the doe cull does not occur.