Weather is your BIG enemy here.
It is tempting to split your forces in half and try the two pincer envelopment of Vyazma from the north and south. This splits your forces too much. It can be achieved but results in a costly delay that then means you run out of time at the gates of Moscow.
Think outside the box.
Better is to defend Safanovo with one infantry. Send one infantry to sneak up on Zhirkovsky but delay that capture.
Send the REST of your attacking force along the the southern axis to take Vyazma from that one side. Be patient till the weather clears and lets you move...After you have captured Ugra and Yukhnov, send a smaller mobile force (armor, with some mobile artillery and at least one infantry!) along the very lightly defended axis of, Medyn, Obninsk, Airfield** (!) at 40,10 and lightly defended Moscow! Scoop up the prestige! You will want to capture Kaluga (hint, hint!). Airfield 40,10 critical. Capture Moscow!
Do this before the weather gets really bad** the last few turns.
After capturing Vyazma with your strong concentrated supported attack from the south send a mobile unit or two to attack major objective Zhirkovsky from the rear(!) and capture it with the sneaking infantry unit. The other objective, major objective Mozhaysk can be taken from the rear**(!)after capture of Moscow.
By your command, Herr General.