The Big Whistle - The N.B.A. Ref Kevin Cutler Is the Tall Guy - NYTimes.com
Presence certainly isn't about size, but it can be a positive factor...
I've stepped in to break up a couple almost-fights (taunting/words... everything leading up to the fight without actual contact yet)... I can tell you, if I was 6'8" 270 lbs, these altercations would have ended a lot quicker.