Well, again, your an idiot. ...The injury is only a minor tear, in a completely different location of the shoulder. He could play Friday, if he wanted to. He is CHOOSING to not play the rest of his Senior season, so that he can be available for UT come January.
Go back and watch the play. The injury was not directly caused by his contact with the ground, but by the other player landing on his shoulder at the point of rotation, driving it into the ground and overextending the joint. Unless your "smaller, more compact" running back is also double-jointed, he would be...out for the season with surgery. Height has nothing to do with this injury....
Let me go ahead and debunk your other claims while I am at it. "Upright" runners, whilst not prototypical, are not sure fire disasters either. Notable "Upright" runners include: Hall of Famer (and fellow "tallback") Eric Dickerson, NFL back and Heisman winner Eddie George, current NFL leader Adrian Peterson, top 10 current NFL back Steven Jackson, and the list continues to go on and on.
... This is a trait that Mr. Hurd demonstrates time and again naturally, constantly taking just the right lean into tackles so that would-be-tacklers seem to just bounce right off of him.
Jalen Hurd is an expectional all-around athlete, but when you watch him, he has an obvious extra passion for the runningback position, and it translates on to the field. Every prospective running back could add a little more weight to their frames, and a few extra moves to avoid tackles would be a nice addition, but Hurd is overall an exceptional RB prospect. If the tear was in the same spot, I would agree that injury prone could be considered, but it is not a related tear, the previous injury is completely intact, and though the injury is minor, they are doing surgery not only to repair the tear, but to stabilize his shoulder now so that his body will be fully prepared for football come spring, and so that a chance for reinjury will be significantly reduced. You could make the argument that the Hurd we will get now will be even better, without the wear and tear of an entire football season (along with the inevitable playoffs he would have taken them to), and with a fully healed body. His senior season would have done nothing more for him from a technique or body standpoint but hurt him....this was a very smart move, and one that will pay dividends in his and UT's future.