@Soviet-Steamroller I’ve always found the Stalingrad strategy to be a difficult one, as it’s just too far from Germany’s industrial base. Couple that with the fact that the Soviets can reach both Ukraine and Stalingrad in one turn with mechs and tanks, and it seems like Germany just runs out of steam. They’re not able to effectively crush the Soviets before the US is knocking on their door. If Italy assists, that gives it a much better chance of success, but my Italian strategy is usually focused on Africa and the Middle East.
By contrast, Leningrad is much closer to Germany’s power base, and with transports in the Baltic, it’s generally a simple matter to capture and hold it, using it as an industrial base for the assault on Moscow. Because it takes the Soviets two turns minimum to reach it, it is nearly impossible for them to mount a counter-attack and take it back. Furthermore, the air base allows Germany to keep their air force in play to defend the homeland, while still menacing the majority of Soviet territory.
I also like to wait until G2 to declare war against the Soviets, just to keep Britain guessing. I can see why you’d go with a G1 attack on the Soviets, though, since as you say, it definitely puts them back on their heels. For my tastes, I just find it allows Britain much more freedom and clarity. Without any pressure against Britain’s capital, they can usually build enough navy/air force to make your life miserable.
Again, just my two cents.