Size does matter. That's why there are weight classes in all combative sports. Bigger guys have more advantages, smaller guys have advantages, too, but not as many and don't come to as much of an overall advantage. I'm not sure why you seem to think smaller guys have the edge.
All my fight strategy is based on deliberately injuring my opponents. -
Crippled Avenger
"It is the same in all wars; the soldiers do the fighting, the journalists do the shouting, and no true patriot ever get near a front-line trench, except on the briefest of propoganda visits...Perhaps when the next great war comes we may see that sight unprecendented in all history, a jingo with a bullet-hole in him."
First you get good, then you get fast, then you get good and fast.