Quote Originally Posted by Steve Blair View Post
Another thing that can be overlooked is how you mix those new troops with veterans. There's a fair amount of evidence that doing this mixing while a unit is in combat is a bad idea if it can possibly be avoided (drawn from World War 2 comparisons of practices in Europe and the Pacific by US forces and Vietnam).
If we look at Antony Beevor's book, D-Day: The Battle for Normandy, on Kindle and search 'replacements' we get 39 instances. One as follows:

Replacements joined their platoon usually at night, having no idea where they were. The old hands shunned them, partly because their arrival came just after they had lost buddies and they would not open up to newcomers. Also everyone knew that they would be the first to be killed and doomed men seen as somehow contagious. It became a self-fullfilloing prophecy, because replacements were often given the most dangerous tasks. A platoon did not want to waste experienced men."
Further, in Gen Gerhardt's 29th Infantry Division, a neuro-psychiatrist, Major David Weintrob improved the manner in which "replacements" were introduced into front line units (this being part of Weintrob's pioneering work on combat stress.

Then you move on to the Pacific to get an inkling into the psychology of the group dynamic in combat units:

A rifleman, Brookes was in the line 20 days before he got his first Jap. After that, he said, he ‘felt better – like he belonged.’ Back in a rest area now, Brookes can lie on his bunk and talk and make gags with the older fellows about what happened. He’s not lonely any more. He’s a veteran. - from Pittsburgh Post-Gazette - Jun 26, 1945
Then we look at Vietnam and the FNG syndrome and need to wonder if anything improved.

What of today?