First, couple of clarifications. The main reason the Soviets did so poorly early in Barbarossa, was mainly due to the fact that a paranoid man, one Josef Stalin, leader of the U.S.S.R., initiated a HUGH purge of the officer corps in the mid to late 30's, because he was afraid of being overthrown, and removed from office. Several THOUSAND "disloyal" officers and tens of thousands of civilians for that matter too, were either tried and executed, or sent off to Gulags in Siberia, where the survival rate was exceedingly low. Yes Hitler was not any better, probably worse by most accounts, but don't sugar-coat the Russians either. Early in the war, Stalin also had several Generals executed for cowardice, believing that the stick was better than the carrot. Also, the NKVD troops were the BEST equipped troops in the early Soviet army, and their job was to ensure the the front line troops STAYED on the front line (or risk summary execution for cowardice). German troops treated Russian POW's VERY poorly, and Political officers were executed immediately upon capture (so they wouldn't cause any trouble), and both the Russians AND Germans committed terrible atrocities on both civilians and soldiers. You do realize that the survival rate of German POW's in Russian captivity was about 10%, right? Stalingrad, 90,000 POW's captured, less than 9,000 went back to Germany,after the war, and some not until 1947, TWO FULL YEARS AFTER WW2 ENDED! If you don't believe any of the above, go ahead and do a little researching in a military history or college library, NOT with Google/online searching. Do it the old fashioned way, by reading a book.
Ok, enough about the history revision going on in the forums. I'm a WW2 tank buff and know a little bit about a lot of the tanks in-game. I know a good deal more about German armor, because it amazes me how many different tanks, TD's and SPG's Germany cobbled together in WW2. They also used quite a few captured vehicles too, as did the Russians. The SU 85i, was a captured StuG III that the Russians converted to carry the 85mm gun. There was also an SS division equipped with (entirely?) T-34's, because they captured an intact factory, and it produced tanks for the better part of a year, IIRC. The Marder II was a direct result of the Panzer III's inferiority to the Sovier T-34 and KV series. It was a stop-gap vehicle that mounted the 75mm PaK 43 AT gun, to give the German army sufficient fire-power to knock out the new Soviet tanks they encountered. The Panzer IV/F2, mounting the 75mm L/48 gun was also a direct result of the superior Russian armor encountered on the Eastern Front. Those are a couple of tid-bits off the top of my head.