It has been mentioned by some that there is a distinct pattern and reason for the names of Sonic characters in the different series that exist. Obvious ones such as Tails (for his two tails) and Knuckles (for the strong spikes on his hands) exist. Others such as Cream (light, sweet and innocent is a brief description, even though this one appears mainly to be a joke on "Cream and Cheese"). Even when American's make something involving this franchise it tends to bleed over. For instance, "Rotor" from both the SatAm and Archie series is a mechanic, hence the name fits rather well.
So the idea of "fitting" themes is not a new one in the Sonic Franchise. But what about adaption to the original design? Or better yet, conscious idea when the designs were originally established. Essentially, each character was built for more than just their main ability or their name. The physical structure as well as internal lends each character their own abilities and personality. The following are a few examples:
Sonic: First and foremost he is built for speed. That's obvious just by looking at him but how else is he built? His arms are shorter than his legs, which are also rather long. The scientific build for a perfect runner includes short arms, long legs, and a backside for balance. Sonic also has a tail which aids to keep him balanced while his legs push him along. SEGA's remake image of Sonic for the newer systems also highlights these features.
Some people might believe it silly that Sonic can fall from such a massive height without injury or, in some cases such as Sonic X, take massive amounts of kinetic force against him and still survive. When considered this is almost plausible based on his design. Sonic has broken the sound barrier before. Most people who tried this before the proper design for doing such a thing exploded. Sonic's structure is built to withstand massive amounts of force placed upon his body.