There is a school of thought that, had Operation Barbarossa been delayed much longer, the Soviet Union would have attacked Germany.
As it was, Barbarossa found the Soviet forces well forward of where a defensive line would normally have been established and, as a consequence, highly vulnerable to envelopement tactics.
If the Soviets were moving into position to launch an attack, this would explain their location.
The Germans were surprised to find so many Divisions deployed forward in the Early days of the invasion, and just as amazed at how poorly they were led.
The huge failure though, was the complete failure of German Intelligence to detect the nearly two million Soviet troops deployed in Southern Russia and Ukraine to hold down anti-Soviet unrest in the ‘Stans”.
It was these Soviet units that set back the Barbarossa timetables so badly. The Pre-invasion German war plan never accounted for them, and the supply chain could only handle so much.