Foot injuries are happening all over, including the NFL. Players want light shoes and sometimes they’re too light to provide the needed support/protection.
The S & C guy, in addition to the obvious duties, also acts as the HC’s eyes, ears, and sometime motivator for the long periods in the off-season when the staff can’t directly supervise the players. So the S & C guy has to have the particular trust of the HC. Also if you are trying to change the culture on a team, the S & C guy has to help drive that change, since he and his assistants are there every day in the off-season monitoring/teaching/motivating.
Which is why almost any HC who was not on staff before bring in his own guy.