I won't digress from your observations about different characteristics between deer from different areas of N.J. Liveintrees, but I'm not sure I concur with your observations about "thinning out some younger bucks..." or even harvesting yearling does. Of course it depends upon what studies you have researched and agree with I guess, but you won't see us thinning out young bucks to make room for more mature bucks.
Frankly, I've never noted that young bucks pose much of a risk for older bucks - in fact the younger bucks - at least the smarter ones, seem to stay out of the way of older bucks. I honestly don't believe I have ever seen a study where this was recommended. At any rate, we have been practicing "Let em go so they can grow" since day 1 on our property. Also, our Deer Management Unit is under mandatory Antler Point Restrictions where bucks must have a minimum of 3 points on a side to be legal and at least 4 points on a side for the second buck tag. This does lead to the phenomena of "High Grading" where your better (5, 6, 7 and 8 point) yearlings are subject to harvest but it does protect spikes and forks at least.
I can't say I have ever read anything regarding the harvest of young does either. In fact I had always understood that your deer herd was much healthier if the average age of the does you harvested was 3 /12 years old and younger. Of course there are advantages of having older does in your herd as well. Let's face it, an older doe which can get twin fawns to the "recruitment" age is probably a better mother than say a yearling doe. Old does also know the ropes about migration routes, prime bedding areas, avoiding predators, etc. However, there has also been some recent research into doe harvests which increase the percentage of buck fawns and maybe even reduce the prevalence of disease.
If you have 48 minutes to spare some time, take a look at this 48 minute video of a presentation made by Wayne Sitton who manages the Turtle Lake Club in northern lower Michigan (and other large hunt club properties as well). Mr Sitton actually hired James Kroll (AKA "Dr Deer") to manage TLC as well.
https://www.michigan-sportsman.com/forum/threads/comprehensive-deer-study-a-game-changer.607171/
This presentation was recently posted on the Michigan Sportsman Forums and generated a great deal of controversial views for sure, but I found it very interesting.
Turtle Lake Club is a large private hunt club encompassing some 40 square miles. They harvest tons of deer every year and every year in February they have a doe harvest and perform necropsies on all of them to gather biological data. They invite biologists from the Michigan DNR every year to attend these necropsies and have been doing so for many years so they have compiled an enormous amount of data concerning average age of fetuses, average size of fetuses, exact sex ratios of the fetuses, and the exact age of the mother, among other things.
What was interesting to note was that younger does (yearlings and 2 year olds) have a much higher percentage of buck fawns and does 3 1/2 years old and older have a higher percentage of doe fawns. Of course, we all know about yearling buck dispersal and the fact that an orphaned yearling buck has a much higher likelihood of staying in the home range where he was born vs dispersing some distance to a new home range, but the bottom line in the TLC research is that you can use this information as a management tool in managing the deer on any given property (given the fact that you have enough acreage to manage).
For example, if you have a high deer density and want to reduce it, you may want to harvest older does to reduce the number of doe fawns being recruited into the herd. This strategy would also increase the number of buck fawn recruitment.
Getting back to antler growth as a regional influence, there really isn't much question that certain areas of the country (or individual states) have the ability to grow better antlers than others. If you happen to own your property and hunt in those areas you will likely see (and harvest) much better deer than other areas. If your property isn't in one of those mega buck areas about the best you can do is provide your deer with better nutrition (habitat improvement) and age (trigger control). I don't subscribe to any type of efforts to "cull" certain deer (especially young bucks) to attempt to influence genetic makeup on a free ranging deer herd. I have seen sufficient studies to refute proponents of that theory.
I guess we just happen to be in one of those parts of the state where we just have to do what we can to provide our deer with the best groceries that we can and give them a little time to maybe grow into the best that they can be given the potential they do have.
