In order to delay a German crush on Moscow you will need the help of US/UK.
The Allies need to at least threatening a landing on S.Fra, Normandy, Norway, Denmark, N.Ita or S.Ita. Everything else is bogus. If you can’t Force Germany to build some ships then they will have free hands on Moscow and it will not matter what they do or how they die.
And, when Germany captured Moscow, they will be in London/Cairo in No Time!
Germany has to send all his assets towards the East. Everytime Germany has or needs to build ships is one to two units less who can march towards Moscow.
If you want to delay a German march towards Moscow, then build up a JFK devinsive line.
J= Novo,Bela,W.Ukr, Ukr, Bessa
F=Bela,Smolensk, W.Ukr,Ukr, Bryansk
K=Smolensk,Bryansk,Rostov and Russia from where you refit and supply your troops.
You have to time it and have to be powerful enough to knock out any Ita Canopeners.