Wow, that was an interesting article, thank you for posting. I'm impressed that someone has gone to the trouble to do this analysis. I tried to access the links they provided to "Football Outsiders" but I could not find a way to get them to open. My google chrome couldn't open them. But either way it was nice to see how they approached the topic and the detail they focused on.
As far as the RB position goes they stated: "RB shows an increasing injury rate based on size up to a point, then a decreasing injury rate. This pattern may again be because two slightly different position groups (HBs and FBs) are being lumped in the same category together."
But as I took a look at the history of the top 10 or 25 RBs I found that many of them were much smaller than I thought they would have been. In view of the article you linked to and what I found on my own, I think I was a little wrong in ascribing "smallness" to injury history. Some of the greatest RBs have been "small" in my estimation.
