With all due respect, that's got nothing to do with it. All his models are over-exaggerated in pretty much the same way. In fact, Rebecca happens to be more on the "lean" side, as ridiculous as that sounds, compared to the others.If Jackerman would make his models have proportionate asses and legs like normal hotties, his models might win. Imagine Rebecca or Jenny with tight, apple bottoms and lean thighs instead of the fat monstrosities they've become. How hard is it to just stick to the tried and true formula - giant tits, hourglass waist, tight heart shaped ass and lean thighs with sexy gap.
The "remakes" he does to the cartoonish characters look much more like his originals' proportions than they do the actual Lady D, Dexter's Mom, etc. Which is why this whole exercise of switching to "mainstream" characters seems pointless.
I'm pretty sure people are not voting Lady D and Dexter's mom, because they think Jackerman's going to portray them 1:1 with the cartoon/in-game forms, they vote for them precisely because they want to see him alter them like his original characters. That and the bestiality angle, of course...