"Twice the size of them.."

One thing I learned early on is that size does NOT matter. An old addage states, "Dynamite comes in small packages." That has been proven time and time again. I have been to matches where a five foot, 160lbs kid KO'ed a six foot 200lb adult in seconds. I've seen the same with wrestlers, martial artists, women versus men, etc. It is all about skill. The only time size comes into play is in depth and reach, but anyone with a first years knowledge knows how to overcome that.