2" just has more cutting area so more likely to hit bone and stop, also 2" is bigger than 1 3/8" so its like raming a 1" pole into dirt vs a narrow 1/4" pole. same force pushing small dia. into body vs. that same force pushing something larger. though all the pene. problems I've heard with the rage are suspected, never actual, kinda like worried it'll hit bone and stop etc.....though I know a guy take an elk no prob with one, and a whitetail. only heard good things so far. and worries. 2" does seem big, but I'd take them over the 3 blade with less cutting area.