An excerpt from “Standing Fast: German Defensive Doctrine on the Russian Front During World War II. Army Group received six brand-new German divisions in Jun 1943 but by 1 Oct the Army group declared these units “no longer fully reliable”.
By autumn, several newly raised German divisions, hastily consigned to Army Group B in June in order to flesh out its order of battle, were also causing some concern. For example, barely days before its preliminary June attack on Voronezh to secure the German flank, Second Army had received six brand-new German divisions. Though game enough in their initial attacks, these units quickly began to unravel due Tu poor training and inexperienced leadership. In one case, the 385th Infantry Division reportedly suffered “unnecessarily high losses” including half of its company commanders and five of six battalion commanders in just six weeks, due to deficient training. This fiery baptism ruined these divisions for later defensive use. The loss of so many personnel in such a short period of time left permanent scars, traumatizing the divisions before time and battle experience could produce new leaders and heal the units’ psychological wounds. Second Army assessed the situation on I October 1942 and informed Army Group B that these once-new divisions were no longer fully reliable even for limited defensive purposes and that heavy defensive fighting might well stampede them. Unless they could be pulled out of the line for rest and rehabilitation, these divisions, which accounted for nearly half of Second Army’s total infantry strength, could only be trusted in the defense of small, quiet sectors.
“Standing Fast: German Defensive Doctrine on the Russian Front During World War II. Prewar to March 1943” by major Timothy A.Wray, USA, 1988 [On line at http://www.stalingrad.com.ru/history/doctrine/charter_1.htm]