Former Sega developer Ryoichi Hasegawa says that Nintendo was adamant that Mario should always be a step ahead of Sonic in promotional art for their Olympic team-up.
Frankly, Mario & Sonic at the Olympic Games doesn't make a lot of sense conceptually; when it comes to the footrace events, having the "fastest thing alive" take on a slightly overweight fella from New York who eats pasta and mushrooms exclusively seems like a weird choice. But then, when you look at trailers or artwork, Mario is always keeping the pace and even slightly ahead of Sonic, and it turns out that was apparently intentional.
