The Omaha Beach guys were mostly 1st Infantry Division with many long service people and recruits from 1942 and 1943. The 1st Infantry Division was reliable throughout the war.
Okinawa was Marine Corps and what, two Army Infantry Divisions?, men who largely had been in the theater for some time. The problem with recruits did not become serious until the second half of 1944. I did not include the Marines as having problems with recruits. The Marine tough training technique was accepted by the public and politicians because "the Marines are tough".
The guys who held out at Bastogne were the 101st Airborne who were long service and volunteers. Their replacements were volunteers also. Anyone unwilling simply decided to flunk jump school. The 101st was sent to Bastogne because other reliable Army units were in very short supply, again, because of poor replacement quality and incorrect training caused by political decisions.
You will find a lot of 1942 Pacific War vets, Navy, Army, and Marines, complaining in their memoirs about the junk men they got sent from middle 1943 on. They were uniformly described as self pitying whiners who would not pull their weight.
Good infantry junior officers were so short by fall 1944 that aviation cadets and others of similar quality were transfered to the infantry. Often those lads really raised a ruckus when told of their transfer. The were told that they could resign their commissions if they wished but would then finish the war as infantry privates.
There was real worry that the usable infantry and armor units would run so low on good men that collapsing morale would make them ineffective. This did not happen, of course, except in a minority of units. The Germans surrendered first.
Imagine drafting DU types and others like them, some not as bad and some much worse. Gang Bangers. Inner city lads. How would you train them to be good soldiers? Well, it can be done. Marine training before about 1955 would do it. There would be deaths in training and sometimes quite a few. Some German elite units (German troops were combat trained by the units to which they were assigned) had one man in ten killed in training. Not by accident, you see?
I have about thirty running feet of shelves filled with books on war. There are also some boxes full in storage.