Very true. It doesn't matter how big you are, that's just one factor. Skill and determination play a big role. I train in japanese jujitsu, juko ryu judo, and western style boxing. In jujitsu, being smaller and flexable is better than being big and bulky. I'm 235lbs, and one of my best grappling partners is 145lbs. Just my thoughts.....
A better debate to start would be Stand-up Arts (aikido, karate, tae kwan do, muay ti, kungfu, etc) vs. the grappliing arts (jujitsu, brazilian jujitsu, wrestling, sambo, and even judo maybe.)
How many times have the stand-up arts won in No Holds Barred fights compared with grapplers? Not many times. I believe the best combo is wrestling, jujitsu, and boxing. ***Muay ti*low kicks man, low kicks!* + JJ/wrestling takedowns*** Those together are so difficult to beat.