They get experienced before they get killed..... fine, then, trained soldiers with some degree of low level experience. It's not, I think, historically unfounded to suggest long, full-on 'total' wars tend to see attrition forcing the sides into using less and less adept soldiers as manpower and time dwindle.
This I can agree with to an extent. There is a period after commitment to combat for the first time where effectiveness grows, then it starts to drop off sharply unless the unit is pulled off the line. For WWII the US Army pegged the average cycle at roughly 45 days on the line. However, this is combat fatigue, not the loss of experienced people. Pushed far enough it will become the loss of experienced people when the effectiveness of the unit collapses (which was 90 days according to the study cited above). The law of averages basically ensures that as long as you have a significant number of survivors your number of experienced soldiers will increase.
While it is fair to say this does not appear to be historically borne out by US WWII experience, it must also be pointed out that this problem could be charged to the replacement system in place at that time, which was described in postwar studies as "the numbers racket" and bitterly indicted for its failures both at the replacement depot and in keeping units on the line without rest for much longer than they should have been. The British Army did much better in this particular area. The Wehrmacht's system hasn't apparently been studied much (perhaps the records are lost?), but as any Russian soldier could attest, despite continual defeats since Stalingrad the Germans grew in technical proficiency despite shrinking in numbers.
Much of the commentary about the collapse of the skill level in German forces in WWII misses a key point that rather than a collapse of regular army or Waffen SS units' skills, it was based on the fact that they were encountering a totally new set of troops, the Volksgrenadiers and other ad-hoc creations being new and not of the same calibur.
(moreso, isn't "steel my soldiers hearts" about a US division on and after D-Day? That's scarcely the start of the war - the US war, perhaps, but not the allied war in Europe)
It
is the start of large-scale ground combat for the Western Allies. This is a telling point, actually. The British Army had not committed large numbers of its troops to the Med mainly because of US threats to send all their people to the Pacific if the Brits weren't going to get serious about a cross-Channel invasion, and frankly the Brits hadn't done particularly well up to that point in the war; their major victory at El Alamein was against an outmanned and chronically undersupplied Afrika Corps which had nonetheless driven them back almost to the gates of Alexandria, they surrendered to a numerically inferior Japanese army in Singapore and Malaya, and they hadn't demonstrated much of killer instinct during the pursuit of the Afrika Corps or fighting in Tunisia, Sicily, and Italy. The US Army had not committed a significant fraction of its strength to these same operations either, nor had it performed particularly brilliantly in Operation Torch or Tunisia. It fell to the US Navy to save the landings at Sicily and Anzio when German tanks reached the beaches in both operations. (Good as the Tiger and Panther were, getting hit by a 5" Common round from a naval gun was, and still is, a death sentence to a tank.)
Until D-Day the majority of the troops the Western Allies had were not committed to operations and had no real combat experience. So, it may not have been the start of the war in Europe, but it was the real start of the ground war.
