I have always considered it more about weight related to hight. Of course the average pro I would think is shorter than average with narrow hips. There are some short pros who are heavy and strong like Jon Dixon and Jamie Foy. Those to are called fat alot in the media, but if you see them in person they are very naturally muscular. They are almost built like gymnists. The perfect gymnist is fairly heavy and very muscular. That is somehow the perfect weight and muscle ratio for throwing you body arround.
All the tall pro skaters, and there are very few of them, tend to be fairly long and skinny: Figgy, Reynolds, who else?
I guess exceptions to the rule would be Brian Anderson or maybe Arto (he was super skinny though, when he won soty) who at least when they got older seemed to get wider? Is Chriss Cole tall?
What would a super athlete skateboarder produced in a lab look like? I am shure the chinese are already working on that problem...