Today I was thinking; the dropships in Aliens are basically LCVs so their crew are Navy and enlisted, rather than being Marine aircraft, which would make Ferro at least a Lt. senior to Gorman, therefore the obvious replacement once he's incapacitated. I mean the entire movie is weirdly unnecessary (if you needed to get rid of someone who works around heavy equipment/pressurized areas, would you send them to a different planet?) so plot hinging on weird joint operations CoC doesn't change much.