In an effort to get dialogue going, I put 6A as the weakest division in another thread. As Chief has shown, there is nothing weak about the number 1 ranked wrestlers in 6A. I think that goes for all of the divisions. When you look at the elite wrestlers from any division, they are tough tough kids. 6A has always had very good wrestlers at the top.
I think a lot of people have historically felt the the depth in 6A was less than some of the other classifications. I think in at least some cases that was a valid point. There were not very many 6A schools, resulting in kids qualifying in 6A that probably would not have qualified in say 4A. That is still somewhat true today. Ignoring disparity in toughness of regionals, with 32 6A schools, the top 50% qualify. In the 64 4A schools the top 25% qualify. I don't mean to discount anyone who qualifies for state. It is a tremendous accomplishment no matter what classification.
I don't have the actual history of 6A schools, but I'm pretty sure it used to be somewhat less than 32. Now there are as many 6A schools as 5A schools and it is full of truly tough wrestlers. Many of the states toughest ever have come from 6A, but I don't think you can accurately evaluate any of the classifications based entirely upon the top tier wrestlers. I think #25 in 4A beats #25 in 5A and 6A most times.