Despite this formal separation, the Einsatzgruppen and the German army frequently worked closely together. The Einsatzgruppen relied on the army for logistical support, transportation, and security. In many cases, the army provided the Einsatzgruppen with maps, intelligence, and access to prisoners of war. In some instances, army units even participated directly in the massacres carried out by the Einsatzgruppen.
However, there were also tensions and conflicts between the Einsatzgruppen and the German army. Some German army officers were disturbed by the Einsatzgruppen's methods and sought to distance themselves from their activities. Others resented the fact that the SS was given preferential treatment in terms of resources and supplies. In some cases, army officers reported the Einsatzgruppen's atrocities to their superiors, but these reports often went unanswered or were ignored.
Overall, the relationship between the Einsatzgruppen and the German army was characterized by a mix of cooperation, rivalry, and tension. While the two organizations worked together to achieve their shared goal of conquering and pacifying the occupied territories, there were also significant differences in their methods and motivations.