Having had the privilege of hearing a few Vietnam vets speak frankly, some of the ways they "interacted" with Viet Cong could have been mixed in with the exploits of anti-partisan Kopfjäger without one realizing the difference. A friend who sustained several wounds in Iraq, including a disfiguring face wound, and worse lost a lot of friends in the early part of the war, talked about some instances while he was serving as a Fister of observing Rangers cleaning house against Iraqis who had been smiling, waving "civilians" moments before. As far as I can tell, soldiers just don't like partisans, and some of their methods, while not PC or delicate, are hard to condemn when you hear first hand.
Atrocities were of course committed by the Wehrmacht against enemies other than partisans, but the crimes weren't rampant or systemic. Having recently reread Band of Brothers -- even our own troops, who along with the British were without a doubt the most Christian and nobly-behaving troops in the war, had issues with some men murdering prisoners, shooting down disarmed and wounded enemies, etc.
After they had been taken prisoner and passed by the front line troops to the rear. ....................... I can visualize the faces of the Wehrmacht Commanders looking at each other and commenting;Schauen Sie sich diese Linie von Gefangenen an, wo werden wir Sie hinstellen? Wer wird Sie füttern und Sie schützen? Wir haben nicht darauf vorbereitet. Ah yes the opportunities they had to take Russia and they dropped the ball. With the purges of the 30’s continuing in Russia, they took in all those prisoners when in reality they could have been turned and used to liberate Russia. Had they done that and won we would not be as we are today. Germany with access to Russia’s wealth of natural resources in their hands would have have fulfilled their age long dream of world power. Luck was on our side, as Ike said;”Hitler is our greatest secret weapon”. I loved IKE! Wish we could find another.