First Special Service Force was nicknamed "The Black Devils Brigade" not the dirty Dozen. FSSF has a fictionalized movie
"The Devil's Brigade". The Dirty Dozen was a total fabrication from start to finish.
FSSF was THE elite mountain unit no matter what the 10th Mountain says. The unit was not made up of criminals, misfits, or incompetents. These men had to be tough outdoor men. used to the harsh climates, bitter cold, mountain climbers.
The FSSF learned parachuting, skiing, mountain climbing and a little underwater demolition and fit enough to carry 100# on their back up a sheer cliff. FSSF usually worked at night: black uniforms, black shoe polish on their skin and a very thin Stiletto,the V-42.
There are some very good books by US and Canadian historians. They left cards stating "The worst is yet to come."