Tell that to Jason Bergmann.
He is 5'10" and 270. Right now he is 4th in the Super Series, and has gone to WOrlds twice taking 9th the second time. He can deadlift as much as Shaw, load a 520 stone to 58", run with a 1000 lb yoke, and pretty much push just about any of the big guys out there. As an example, Poundstone has never beat him in the stones and he is several inces taller and has about 90 lbs on him.
In other words, size doesn't matter. ABout the only time you might notice it is in a truck pull where the mass of the competitor does reflect on the speed of the pull. But then again, when they pulled the C-130 at WSM in Charlotte a few years back, tiny little Bergmann took 5th.
B-