I have just finished a series of 3 games as Axis vs human Soviet. One was a PBEM (Sledgehammer AAR) and 2 were server games. I think one of my opponents was very experienced and 2 probably had played more against the AI Axis. While I have played only a couple of times as Axis, I am pretty fast and pretty good at moving up infantry. These games all ended with the isolation of Moscow (turn 16 and turn 11) and one on turn 6 where Leningrad fell to a coup de main on turn 5 and turn 6 found an axis breakthrough near smolensk that ended with a large pocket and armor exploiting to vyzama and rchev areas.
Two observations I think may be of interest to a wider audience. One is how Resting panzers recovers thier power. Generally, lets say we are in AGC and turn 4 ends with soviets retreating and the panzers while moving and attacking that turn, ending the turn out of a zoc. At this point cv's may be 10 or smaller and fatigue 70+. Turn 5 is a rest turn. No panzer movement. This allows you to automatically pass your admin check for fuel and maximizes fatigue reduction. Turn 6 you again start not in a zoc maximizing fatigue recovery. At this point your panzers are almost fully recovered, CV is 14-16 and fatigue under 10. This short pause really helps fatigue recovery which dramatically restores panzer effectiveness. Another turn of rest fully restores panzers. Remember fatigue really reduces combat effectiveness.
Not moving panzers is hard to do when you feel the pressure to attack so hard in 41 so as not to let the bear get too strong. However, this pause also lets your infantry catch up and pass the panzer spearhead. This is the second observation, soviets seem to underweight the threat of german infantry near the front line. I have found that concentrated infantry that is close enough to the front line to launched deliberate attacks is deadly. Soviets seem to think level 2 forts in good defensive terrain are worth defending.
During this early stage of the war, these level 2 forts exist to dissuade german panzers from launching hasty attacks (and they do this well). But they really do not dissuade a prepared Axis. I generally try to stack 8 or more pioneers at AGC headquarters at this stage. This allows me 2 or 3 attacks where I am pretty sure I will bring the fort level down 1 or 2 times before combat. This means my infantry deliberate attack will rout this stack in a high odds attack. Since I am concentrating on creating a 3 hex Panzer Punture, most of the first and some of the second line will be breached by infantry before the panzers even move. With panzers rested as above, very bad things can happen.
Lesson for Soviet, when german concentrates infantry at a front you cannot hold. Do not love those forts too much, just continue running. You need 2 things to successfully decide to try and stand. You need to be able to flood the area with units. This means multiple stacks of 3 units. You really can only do this near moscow and leningrad. Second, you need to reinforce these units because they will all need to be replaced after 2 turns or so of combat as they will be fatigued and morale challenged. Soviet divisions with a 1 cv cannot be in the path of a major axis assualt. They are route bait.
Hope people find these observations helpful.