Size is one of the many components of Bodybuilding. Symmetry, proportions, condition, balance, roundness, structure(waist/shoulder width...) are much more relevant and fundamental components. Very few man are bigger that Paco, kovacs and so on....that does not make them good bodybuilders by no means....
Dexter is probably one of the most genetic gifted Bodybuilders of all time. Small joints, tiny waist, amazing separation and condition, great shoulder width and so on....If you think he should not be MR O...you just ignorant that all.