Noted.
You just picked 5 out of 7 guys that are bruising runners. Ty looks like a poor mans Matt Forte. And height can be important, it makes alot of runners run tall instead of staying low.
I'm not sure what the 5/7 line is intended to point out. I tried to represent a spread of runners: Deuce ran extremely upright (way more than Isaac), but was fast, had exceptional vision, and knew how to lower his shoulder when it mattered; Taylor was an exceptional athlete; Jacobs was a freak with below-average vision and limited agility; etc.
I think, more than any other position, we fans misunderstand what we're seeing with running back height/weight/speed measurables. If you were to survey the landscape of great college backs, you'd probably find that the overwhelming majority were within a couple of inches of 5'10, within say 10 lbs of 210, and run about a 4.6 +/- 0.1. As you moved up or down in height/weight, you'd see a dramatic drop-off in numbers. We look at this and say "5'10 210 is the ideal size for a running back." But it strikes me that 5'10 210 is also the most common body type for an athletic male -- i.e., 5'10 is average male height and 210 is about what you'd expect an average 5'10 male to weigh after 4 years of college-level weight training. There are simply more of them. And the distribution of athletic men certainly mirrors what you see among running backs. So, looking at the distribution of RB body types cannot, by itself, tell us whether having the typical body type is advantageous.
For that, you'd need to drill down deeper into the data. Do taller/shorter high school backs fail to live up to their ratings more often (assuming the ratings aren't already adjusting for height)? Do taller/shorter backs become bruisers/speed backs with disparate regularity independent of weight? If height is detrimental to body lean, why don't we see more MJD-type backs at the elite level? Etc.
My amateur guess is that what we'd find is that height/weight/speed measurables are fairly non-predictive of RB success and even of RB style. We focus on them because they're easily comparable, but they're way less important than more nebulous traits like vision, balance, and patience. Take an example from the backs I mentioned above. Michael Bush is one of the bigger backs at the NFL level and he accelerates faster than Deuce McAllister, who was a long-strider that built a head of steam over time. Given those two factors, we know that, as a matter of physics, stopping Bush requires way more momentum than does stopping McAllister. He runs with better body lean as well. Watch their tapes, though, and there's no way to argue that Bush is the superior bruiser. McAllister simply excelled at the qualitative dimensions of running over a guy: he had incredible balance and the innate ability to make contact at just the right angle to put the tackler in the ground without going down himself.
The Forte-Isaac comparison seems appropriate. Their tape looked somewhat similar, although Forte was much more raw than Isaac coming out. I remember when Tulane grabbed Forte (before moving on to ND, I graduated from Tulane shortly after Forte started there), he was expected to be too big and too slow to stay at running back. He was brought in as a fullback recruit, but his talent as a running back was too obvious to ignore.
