I think people are overlooking the fact that DUSTies simply wouldnt fear death, and really, really downplaying what that would mean in actual combat. Combat is not a video game. Its intensely scary, frightening, visceral, emotional, even for the best and most well trained soldiers. People dont want to die. Dont fool yourself, even the most elite soldiers will literally shit their pants and whimper during say a brutal and intense artillery barrage.
Fear makes people do dumb things, makes their hands shake, makes it hard to make good decisions. Its mammalian, instinctual, it happens even in the best units. Even units trained "to not fear death" are often indoctrinated to a point were their battlefield performance suffers in other ways. (ex: Japanese soldiers in WWII were indoctrinated to not fear death....which is one reason why the US Marines killed them at a ratio literally greater than 20 to 1. They wanted to find death in battle, and they did.)
DUSTies wouldnt have that. They simply wouldnt worry about it. Its not an emotional event for them. They could be completely rational and calculating at all times. I think their battlefield performance would reflect it, would give them a huge edge, to the determent of even the most elite opponents.
I'll take 100 DUSTies over 1000 elite soldiers any day of the week.