The rules for receiving the CMB have changed. Considerably. In my day (VN) to receive the CMB, one had to be a medic assigned to an infantry unit. Those assigned to arty, aviation, etc. were ineligible to receive the CMB, even though many were in intensive combat. Such is no longer the case.
Note to self and others who may be interested....Nearly 6K NG’s and ER’s were KIA in Vietnam. Joining either Component was hardly a ticket out of combat...