Losing 19-16 in OT, when your offense is just about as inept as your opponent's, is not what I'd call having that plan blow up in your face.
Over a third of Weisman's total came on the final drive. He'd be contained as well as you could expect for almost the entire game (70 yards on 20 carries before the GT drive). Iowa had fewer first downs (a miserable total of 12), was outgained (328 MSU, 257 Iowa), and had more penalties.
Tell me again how Vandy made MSU look foolish for loading the box?
You also aren't taking into account that while MSU has arguably the best defense Iowa will see, they also have arguably the worst offense. Northwestern and Indiana may not have great defenses, but for whatever reason, Iowa has struggled to score points on them recently. And they have very good offenses.