Sometimes, antlers are funny things.
The first full year (2010) on my panhandle place, I got pics of 12 different bucks from pretty much all age classes that had a strong right side and weak left side. It was actually amazing to look at and study the pics. I thought I bought a place that had some really funky genetics or I had a bunch of hybrids.
The following year, and every year since, the herd bucks were almost perfectly balanced.
As far as explanation, I got nothing.