Call me crazy,but I distinctly remember Col Thorwald specifically mentioning "Maj. Roosevelt" during the film...and FDR's son Maj Jimmy Roosevelt was indeed the XO of 2nd Marine Raider Battalion and a member of the Makin Island raiding party....but no mention is made of him in the IMDB credits for the film...and I remember hearing somewhere that Maj Roosevelt made a cameo appearance playing himself in a couple of scenes in the film, subsequent to the actual Makin raid
shareMaybe they included a mention of him by name for authenticity, but left out the character so that they did not need to fret about who to chose to play the President's son, and all that. The XO is an important part of battalion leadership (been there, done that), but it's a position that can be ignored for dramatic presentation. The XO is mostly working with the staff and following up on the small stuff for the commander with the company staffs. Lots of paperwork, lots of coordination, but when the shooting start the XO is usually one more rifleman.