Case 103 says, "... the interpretation of 'seamanlike way' must be based on the boat-handling that can reasonably be expected from a competent, but not expert, crew of the appropriate number for the boat." That works well for cruising boats, but not so well for one-designs.
One-design sailing isn't really a one-design competition unless you have one-design humans. Large skippers can have a boat-handling advantage in keel boats, while smaller sailors will have an advantage in most dinghies. You can also consider events where disabled sailors a racing against able bodied sailors. Competence may have little to do with the boat-handling. Examples of problems are an inside boat at a mark not being able to turn as quickly as expected by the outside R-O-W boat, or a boat tacking to starboard and a port tack boat responding slowly, due to physical differences.
How might Case 103 be reworded to allow sailors with physical differences to race against each other?