as you like to say, Ronnie does need to be bigger than dorian to beat him.
also, I would not call a 7 pound difference at the same height "dwarfing" 
i dont know about that.
i know what the weight says but keep this in mind.
paul, nasser, fux, louie, francois, etc. never drawfed dorian. paul and nasser had at least 20 lbs. on him.
ronnie was seriously dwarfed in 98 by nasser.
that's why despite what ronnie weighed in 03 and 04, it wouldnt have that great of an impact.
that fact that yates weighed on 260 and is the densest (for your pumpster) bber of all time allows him to compete evenly with guys who are heavier.