Well, what you wrote that follows is mostly complete bullshit.
When Russia entered the war, they were relying on surplus weapons from WW1. They had no technology and couldn't even produce ammunition for the Mosin Nagant bolt action rifles they used in the infantry.
The Russians had plenty of modern weapons available in 1941 when Germany attacked. They had the largest tank park in the world, by far. They were producing modern arms. You mention the Mosin Nagant rifle. It was pretty much the equivalent of the German Mauser K 98 that was the most common rifle in use in the German military. The Russians were also producing the SVT 40 semi-automatic rifle, and PPsH 40 submachinegun. Their artillery park was mostly modern pieces in 76mm, 107mm, 122mm, and 152mm.
FDR sent modern machine tools that industrialized Stalin overnight. General Motors sent an army of engineers to design the T-34 tanks that the Russians used. Russia never did develop any sort of useful air force during the war.
This is complete and utter nonsense. The T-34 was designed starting in 1939 well prior to WW 2. The same goes with the KV-1 heavy tank. The Red Air Force used primarily Russian designs, with the most common coming from the Yakovlev, MiG, and Lavochkin bureaus for fighters and Petlyakov and Tupolev bureaus providing modern bombers. They focused their air force on use as a tactical arm rather than for more independent operations.
German arms are every level were massively superior to those of the Russians. But the T-34 was cheap and disposable. Stalin threw them at the Germans as cannon fodder. Short on steel and fuel, the Germans couldn't afford to lose any armored vehicles. They were tied down in Western Europe and North Africa, cut off from both oil and iron that they desperately needed.
Actually, most German arms were not really any better than other nations, and often worse. Virtually all German technology was no better than on par, and often far worse than Western Allied technology in the same field. There were few areas where the Germans held any advantage whatsoever by the beginning of 1944. There was never any shortage of iron for raw material to make steel in Germany. The only thing that limited production for virtually the entire war was capacity at steel mills to turn out product.
The much maligned British fought brilliantly by cutting Germans off from the resources they needed. Had Hitler NOT attacked France and Britain, those resources would have overwhelmed Stalin - even if FDR were still aiding his Comrade mass murderer.
Without defeating France, and taking Czech industry, the Germans couldn't have invaded Russia at all. In 1939 when the war started about a quarter of all German tanks were Czech models made by Skoda. Skoda also was the source for much of the artillery going into newly raised divisions as the war expanded. Whole German divisions were being equipped with captured French, Czech, Belgian, Polish, etc., weapons such was Germany's shortage of everything.
Britain, up to the US coming into the war was hanging on by a shoestring. They had no capacity to conduct any grand offensives, and most of their defensive operations against Germany had ended in utter failure, like Greece, Crete, or N. Africa. At sea, the RN alone didn't have the ships, aircraft, or anything else to defeat the U-boat campaign Germany was waging. That took the US who dumped cubic dollars into that campaign to the tune of about $10 billion or the equivalent of 3 Manhattan projects.
Take this example: In the US and British military, training troops to drive vehicles was a minimal task. Most men already knew how to drive and had some mechanical ability with vehicles. In the German military, troops that were to be drivers usually had to be trained from scratch as they had never operated a motor vehicle. The Russians had the same problem but dealt with it differently by giving only the minimum training to get someone in the vehicle where they were expected to get better on the job.