There was probably a bigger chance back then (even early 2000's) that guys would stay under the radar. They didn't have all of the resources they do now for expanding their reach to more recruits for evaluating and getting them "rated."
Also, I'm sure a few of those guys listed weren't all unanimous 2 stars or lower. There are probably some mingled with one service giving them that higher rating. And in general, due to the statement above, I'm sure a few more of those guys would have been rated higher today. There's a good chance that an under the radar guy back then was higher caliber than one today.