I'm short - 5'9, but I'm big - around 230
http://www.geocities.com/kalistawarrior/sevenstar.jpg
Don't fall into the misconception that big guys are sluggish. And even if they are, they can make up for it in other ways, like power and pain tolerance. In my longfist days, I was one of the most flexible kickers, and was doing things such as tornado kicks with ease.
Yes, Men at Work was a decent band.
bigger opponent = bigger target... true. Let's not forget:
bigger opponent = more weight to deal with if you go to the ground
bigger opponent = more mass to pound on you with
bigger opponent = more size to crowd you with