When I said "the Soviet Union of the 20s and 30s", I thought it was clear that I mostly meant the latter part of the 20s (after the Poland-Soviet war) and the earlier part of the 30s (before Stalin purged the best military minds of the time). Regardless, the Poland-USSR war took place almost immediately after/during the Civil War, with the Red Army being in the midst of reorganization and many of the White forces either not integrated or still fighting against the Soviets. Anyhow, the Soviet military advantage peaked around 1934 or so, when it's new designs were state of the art and it's military structure was functional. After that, Stalin screwed things up in a variety of ways:
-His purges wiped out the bulk of his officer corps, with the result being that the Red Army of 1941 was horrifically understaffed, with those few officers still around being inexperienced and often incompetent
-He removed the territorial army of the Soviet Union and put it into the regular forces, depriving the USSR of extra competent manpower when it was needed most
-He appeased Hitler by providing him raw materials even when it was obvious Hitler was planning an attack. He also had anyone who pointed out the obvious imminent invasion arrested.
-When Hitler attacked, he required his officers throw their forces into bloody meatgrinders rather than fall back, resulting in massive losses for basically no gains.
-He was sufficiently tyrannical that the Nazis were able to recruit many Russians into anti-Soviet forces (an impressive feat considering how the Nazis treated those in the East)
Industrialization may have been slower without the Bolsheviks and, to some degree, Stalin, but its worth mentioning that Russia was already on that road as of the 1890s, and likely would have had a fairly strong industrial base by the 30s anyway, and probably with less unnecessary deaths too. Anyhow, even if you really like the Bolsheviks for whatever reason, Stalin was easily the worst of the bunch. He had pretty much every other Communist from his time executed for some reason or another.
1) The officer corps had a lot of Old Guard, which was basically those people who made the revolution in the first place. These people have argued at the time that Russia must be used as a launching platform for a massive bloody attack on Europe. These people should not have been in a USSR.
2) Territorial army is not functional, it's corruption hell. I'm not sure why you're so praising it, when it is obvious that the very idea of territorial army is wrong. It's like if States in USA has their own private armies. It's ineffective at defending against a competent attacking army, because it's practically immobile. You know what happened to French army when Germans attacked? Yeah.
3) Dude, Churchill appeased Hitler much more than Stalin, and yet I don't see you blaming him for that. Also, if not for that appeasement policy, the Hitler might have decided to attack earlier than he did in real life, and that would have ended pretty badly for Soviet Union (Moscow, Leningrad taken in the initial push)
4) And yet enough people survived to fall back and form the front in the end, anyway. And the german forces were delayed enough. As many of high german command people show in their memoirs, they were behind the plan since day 1.
5) People like that would have joined Nazis regardless.
It seems that you somehow think that USSR had won the war not because, but despite the Stalin's efforts. I wonder what have you read to make that weird opinion.
1) Only a very few people Stalin purged were "Revolution In Every Country" advocates, primarily Trotsky and company. Most were simply people who advocated things Stalin didn't like or were potential threats. Was Tukhachevsky a Trotskyite? Were Zinoviev, Kamenev, Rykov and Bukharin Trotskyites?
2) I don't think you know what the territorial army was, but it served its purpose quite effectively while it was in existence. Actually, it's a bit weird that you'd be completely ignorant of such an important body, considering it constituted the bulk of the Red Army at one point, but then I hear the Russian education system has been taken over by former members of the organs so I guess it's not so weird.
3) Perhaps appeasement was a reasonable idea in the 30s, when Hitler had some connection with reality, but Stalin gave Hitler war materials well after everyone involved knew that he was planning an invasion. There were trains loaded with raw materials going across the border just as the Germans began their attack. It didn't even deter Hitler; it made him think the Soviet Union was weak and an easy target.
4) The stupid counterattacks were sufficiently devastating to Soviet manpower that such counteroffensive were basically unfeasible from 1943 onwards, whereupon the Red Army began adopting doctrines that had been advocated by now-purged former commanders. I also take it you have no relatives that died relatively pointless deaths in isolated counteroffensives.
5) They actually joined specifically because of measures Stalin put into place. For example, if you were surrounded by the Germans, you were expected to stand and die rather than punch through the encirclement to friendly forces (this is what happened to "grand traitor" Andrei Vlasov, who launched one of the few successful counteroffensives, discovered the forces on his wings were not so fortunate, and was promptly encircled and had his forced wiped out). You were expected to never make a retreat and instead constantly attack, even if you knew full well that an attack would be pointless. You were expected to kill yourself rather than surrender, and if you somehow were "rescued" by the Red Army you would either be imprisoned/executed on the spot (more likely from 1941-1942) or at the very least vetted by the NKVD/SMERSH and have a good chance of being imprisoned/executed on the spot ('43 onwards). Given these facts, it isn't so surprising that PoWs would consider siding with the Germans on occasion, and that's ignoring the various peoples Stalin persecuted specifically like Ukrainians, Kalmyks and Cossacks.
So yeah, I'd say that the USSR won despite Stalin, specifically through a combination of titanic effort from the Soviet people and through the incompetence of the Nazis (Hitler was just as delusional as Stalin was, and his brutal policies relating to the East prevented the creation of anti-Soviet militias that would have easily won the war for him). The only good thing Stalin did was generally get out of the way come 1943.