You're not 6'3, that's why. Measure yourself properly. If you're 6'2, you're not 6'3.I can't speak on all the fighters but I have met a few and I dont think that their stats lie.
I'm 6'3" and when I met Sylvia in Vegas he was every bit of 5" taller than me...it actually seemed like more than that.
I also met Tito and he seemed like he was as tall as me ( and his head looked like a buffalo head!! haha )
I've also met some other fighters... Joe Riggs, Mayhem, Jake O'Brien, Hector Ramirez, Razor Rob, etc when I worked for their agent Ken Pavia ( I work for another company that Ken used to own ). I'm not sure what these guys are listed at though.