A Corpsman trained in triage?
I did several online searches and couldn’t find any reference to such a job in WWII Navy.
I have talked to lots of old guys who would come up with odd ways of describing their military duties, often it was my own lack of listening skills that made me have it wrong. My father-in-law as an example, he talked about being a jeep driver being attached to the First Infantry Division in WW11 which made no sense until after he passed and upon reading his military record I realized he was a Combat Courier. All I ever heard was something about jeeps and getting shelled while driving for it was the way he got his Purple Heart which was the part burned into his mind.