That's maybe the most famous what if of ww2. I don't think Germans could have taken Moscow easily with the full ukrainian army threathening their flanks. And if Moscow capture isn't sufficient to bring Stalin to negotiations, the german are in bad spot for winter with a front line twice longer than historically. So you trade a garanteed success (Ukraine encirclement, 700k troops eliminated in one battle, the biggest victory in all mankind history), for one hypothetical success, but that had the potential to end the war. It's a gambleIf Germany had taken Moscow or even surrounded it in late summer before turning south to the Ukraine
Imho the true strategic mistake is that they planned since day 1 to defeat soviet union in one single 6 months campaign, fearing a western invasion. This stress was the main reason they keep pushing even in November. Staying on the defensive after viazma isn't a gamble, and they could resume their attack in spring 42 after the soviet winter counter offensive failed vs an entrenched wechmacht.
Another problem is : How the AI can handle that? Atm increasing any attrition would led the AI to waste all equipment during the first winter.Needless to say, weather in the game is not much of a factor right now. I do not think the attrition is enough of a deterrent or has enough effect. I still hope it gets fixed. It will take a hell of a lot of rebalancing if it does get fixed. It will also require a toggle on the army screen for automatically halting offensive operations during adverse conditions. We would never be able to keep up with pausing operations during inclement weather, night, etc. manually.