Regarding genetics, there's an interesting Meat Eater podcast out there titled Landscape of Fear. It's got a couple of guys with PhD's from the Muley Fanatic Foundation. They have research that suggests nutrition for the mother while carrying her offspring can play a larger role in predicting the size of a buck than what we call "genetics". They make an interesting and compelling argument. I'm not doing them any justice passing on the Coles Notes version but whether you like the podcast or not it passed on some very interesting information.