Janitor is both right and wrong as far as his comments on Powerlifting are concerned. In Powerlifting a smaller guy can be stronger than a heavier guy, sometimes. Strength depends on a lot of other things than bodyweight only. Notable factors are the amount of fast-twitch muscle fibers that you have and leverage. However, the average bigger guy will always be stronger than the average smaller guy. Meaning, bodyweight do count. Muscular weight, of course, count for a lot but surprisingly, even fat weight sometime count. It is supposed to give you better leverage under certain conditions. I know a bit about Powerlifting because I was the champion of my state and also competed in the national championship of my country, where I represented my state. I competed in the bantamweight and featherweight classes.
Powerlifters, like punchers, have different body styles, though. The World's Strongest Man competition is the perfect example. The guys who have the easiest time with the keg toss are the very tall ones, who can get alot of leverage and arc on their swing, but those are the same guys who suffer from a huge range-of-motion in the deadlift and squats.
They are all built but their shpaes and tales of the tape vary. How tall is Marius Pudziannowski for example?
OK. I am guessing that if he never went into powerlifting and had been developed as a heavyweight from an early age he would a compact Tysonesque puncher, built but not one of the superheavyweights. It is just a guess of course.