I see posters making this mistake all the time:
Defense in 1943-1945 was not the same as Offense in 1943-1945.
To put it mildly, the tactical advantages accrued to the the defender and the Germans were strong and efficient in the defense.
IN comparison, they were weak in offensive capability compared to the Soviets and Allies.
A lot of the Soviet numerical superiority went into Soviet defenses. During an offensive, some of their resources would be used to boost the defensive depth up to 70 KM in critical areas so the Germans would never have the strength to penetrate the operational depths with 'Cannae'( the old German strategy of allowing the Soviets to perform offensive overextension, then cut them off & destroy them with a double envelopment) like counteroffensives. They had learned this from disasters in 1942 and 1941, where the defensive depth was too shallow. (The Soviet defensive depth in 1941 was often just 10-20 KM in places)
They never include the Russians for obvious reasons. Russians won their battles by assaulting the Germans with mass amounts of tanks and infantry, shrugging off losses as long as the Germans got pushed back.
The Red Army also does not get enough credit. It destroyed German forces and conquered more territory at a rate faster than the W.Allies. It did not need a 4:1 superiority to win an offensive; the rest was just a bonus.
Sure, they took higher losses but that was their military model and they got the job done. They did it with less firepower and supplies per capita than the W.allies and they won almost every battle after 1942.
If you want to model this in the game, the German & axis allies would start out with"
an elaborate, pre-established defense network with quick response mobile armored reserves in the rear..(with weeks or months of preparation) with killzones, communications systems, & tactical countermeasures set up... with minefields, traps......with troops intimately familiar with the territory from studying it for weeks/months.... while the Soviet would be the numerically superior attackers attacking territory they only know via military intelligence, recon and probing.
Not Happening.