I agree with Dungey being ahead of RV but figure RV would be right there with the Dunge. RV and Dungey were pretty evenly matched throughout their career but I guess Dungey's longevity was enough to put him a few places ahead. And Stewart had an undefeated season and is 2 positions behind Dungey.
http://racerxonline.com/category/30-greatest-ama-motocrossers
Still one of my favorite races ever to watch.