You're welcome. Two other observations after playing the SU campaign until Feb 1944 (and being on the border of Poland at that time).
First, I never got a second guard unit after the first infantry.
Second, some officers were purged that shouldn't have - Ivan Konev (he is like on the level of Rokossovsky, famous and capable) and Meretskov - he was a high-skill officer who disappeared in the purge in the game, but remained as an option for a Chief of Staff or the other military position in the cabinet. Meretskov became a Marshal and died in 1968 in reality. There might be other "unlegitimate purges"
, but these are the two that made the biggest impression on me.
BTW, I noticed something that might be an illogical game mechanics. I encircled and beat several divisions, who started retreating to a German-occupied province. When they got there, it was already mine, as well as the bordering provinces; I had expanded faster than they were retreating. Instead of disappearing though, they OCCUPIED/invaded the provinces. Maybe I should have left a unit there to technically beat them and then they would disappear, but it does not seem logical IMHO.
Kudos!