ORIGINAL: neuromancer
Back to the situation at hand, I am wondering where all the Soviet units have gone. In my game (T4) they formed a line just in front of Pskov, right across the map from the Baltic to the east edge of the map. Not a strong line to be sure - I have the 4th Panzer Group poking at Pskov while the infantry moves up having finished the mop-up and relieved the panzerkorps at VL - but a line nonetheless.
I decided to write an AAR after playing this game to Turn 10 and did not keep end of turn saves for previous turns. This is the drawback of my using screenshots from start of turn saves to illustrate what happened in the past turn. The Soviets did form a line. However, I found that in the early turns the AI often retreat one or two hexes if they were in unfavourable locations (e.g. in clear hex, not behind river, not in rough/swamp hex). These moved units were not shown in the map when the next turn starts. Moreover, newly occupied hexes and battle sites cannot be shown.
I think the AI concentrated their defence in front of Pskov. See my end of turn note for Turn 3, the Soviets actually kept a whole Army of units there. Separately, I found that for a swift attack on targets 8 to 10 hexes away from the frontline in the early turns, the defence is usually thin. I often encountered only about 2 to 3 Soviets units on the way, and in most case they were no match for advancing German motorized units.