ALL computer games are fantasy. There is no blood, pain, death, dirt, broken bones, severed limbs, decapitated rotting bodies, brain gore and bodily fluid sprayed all over you, no vomit inducing stench of death. No real morale, strategy, tactics, supply etc issues that are remotely the same as reality. No fog of war remotely approximating real life. No bonehead NCO yelling at you to do something that absolutely doesn't need to be done. So, go ahead with the scenario which is the same as the rest, fantasy.
And why couldn't Beria assasinate Stalin and give Germany european russia and bide his time behind the urals? Didn't happen, but could have. What if the Germans got a little luckier in 41 and did take Moscow? Stalin sues for peace and bides his time behind the Urals?
Thus Germany has a huge increase in resources and a one active front war. Maybe also Hitler didn't mistreat the Balts and the Ukrainians? Thus more soldiers. What if Hitler died and someone more sensible took over?
I suggest that they label this scenario as "fantasy" so no one will be confused and think it actually happened.