With how the system is built to add in specifics for missing limbs or other lost faculties would require a MASSIVE rework of the written descriptive text system. Because not only would it have to account for the addition in descriptive text but also in gameplay. Then they would have to rework jobs and school activities as well since some of those the character could not do.
Other than that I do agree tho that the characters can seem very similar. Only a few have unique options.