There was also a question of armaments: German infantry squad had a machinegun as its primary weapon, while soldiers with carbines were to support it. It allowed them great effectiveness in open areas, but they weren't of much use in cities. Soviet infantry squad was planned to be rearmed with automatic/semiautomatic rifles like SVT/AVT/AVS or SMGs like PPD or PPSh (plus PPS later in war), and they were much better in close combat while underperforming in open areaa. Rearmament was completed only partially, and later Red Army focused on SMGs, even creating dedicated "automatic weapons companies/battalions", plus providing additional SMGs for soldiers going into urban battles.

Also Red Army divisions had more mortars then German and that also contributed to their relative effectiveness in urban battles.