We suedo manage our land somewhat similar to you. But we don't shoot the spikes. Nice bucks or does, let all the others walk. IMO, the vast majority of spikes are just young deer. I personally know of one long horn spike about 10yrs ago that the following year was a clean basket rack 10pt. Once they are dead, they ain't getting no bigger that is for sure.
Its gotten alot better over the years, with nothing more than selective harvesting and trying to even out the buck/doe ratio somewhat. We used to see piles of does for every buck... now we see about 3-4 does for every buck.