One of the very few “stories” Dad would tell us about his experience was that he lost all of the first group of corpsmen and writing those letters home was among the most difficult of duties he had.
Statistically, once could infer that thus that 1/14, or 7% of MoH awarded at Iwo would go to corpsmen; instead, it's 20%. That alone tells you something..
If you read the citations for the corpsmen here there's one common element..exposing themselves to enemy fire with absolute disregard for their own life. In some ways, they are deserving of a higher-order MoH, if such a thing were possible..