Only a few were screw ups. The whole "All the Americans are screw ups" angle was pure Hollywood, probably done because "The Dirty Dozen" had been such a big hit a couple of years before. MGM produced both,and were obivioulsy angling for another Dozen with Brigade.

Most were experienced skiers, rangers, outdoorsmen, climbers, lumbermen, miners, hunters, scouts, etc. Very few if any were the screw-ups portrayed in the movie.

There were some that were less than desirable (their commanding officer mentioned it in a document) but they had plenty of good solid recruits too. when recruiting,they were specifically looking for hard-rock miners, hunters, and generally anyone with extensive outdoor experience, that was their primary focus