As the situation on the Russian southwestern front deteriorated and the Third Army Group collapsed, the flanks of the nearby Fourth and Eighth Army Groups faced serious threats.
In order to ensure the safety of their flanks, the Russian Fourth and Eighth Army Groups had to retreat at the speed of the Third Army Group.
The Fourth and Eighth Army Groups were able to orderly retreat, but the Third Army Group, which was close to disintegrating, discarded their helmets and armor along the way in order to speed up the withdrawal, leaving behind inconvenient artillery, heavy machine guns, and some shells, ammunition, and supplies on the front lines and on the road of retreat.
If it weren't for the natural barriers of the rivers from the River San to the Dniester River, the German army might have advanced unimpeded and occupied the entire Polish region.