According to Stephan Marceau overt at Fight Opinion, he sees the the Holman vs. Hamill fight as such:

Rex "Big Dog" Holman vs Matt "The Hammer" Hamill

I dont know much about Rex Holman, except that he is also an NCAA wrestling sensation (as Matt Hamill also is). This is also the battle of the local boys. Holman went to Ohio State and hails from Columbus, while Matt is from Cincinnati. This could be an interesting matchup. We know Matt does not seem to have the strongest chin and tends to swing wildly, so if Rex is any good standing up, he may want to exploit that against Matt. This is one is a pick-em fight I think, with maybe a slight edge to Hamill for being familiar with him.

Marceau is a great writer, so I'm not bagging on him at all.  But I believe his attitude is representative of the larger attitude about who's going to win this fight.  In short, this is why Holman is ranked low and Hamill is the odd's favorite.  It's not because he's bad or has questionable skills, it's because no one really knows a lot about him.  AGAIN, I could be underestimating Hamill and his wrestling.  I realize I'm giving a lot of attention to Holman going into this fight, but it just seems to me people are picking the outcome off name recognition.  It's really going to be a lot closer than folks realize.