The records seem to prove you correct. It's funny, I've looked into that several times and I still have a vivid memory of a tape with Johnny Carson and Lee Marvin where Lee spoke matter of factly in regards to a disability that didn't really effect him much, but he always received something like a 5% disability check, ..seemed like it was a wound to the small finger. He spoke to the efforts of those who walked in from the boats in the surf for about a quarter mile at Tarawa and I've always associated it with him, but perhaps my memory is mistaken,..as I haven't found any other corroboration of that memory on the net.
Marvin was shot in the butt on Saipan and spent the remainder of the war hospitalized. Check your library for the book "Stars in the Corps"