Both are small, both under 5'8" and don't have heavy frames. Manny does have solid legs as to size and that aids him as a welter!
Right now in boxing theres alot of guys who are under sized, Cotto is a very small 54 pounder, Mayweather was bigger in body size than Cotto when they fought! When you compare these men to the greats from the past at welter their very small plus they don't have any power. To me Manny needs to be at 130-35 to be at peak and Floyd can't be more than 140lbs to compete evenly! Against the great welters through the years they both get beat up!!