Most of his contemporaries record night after night of hours-long boozing sessions.
Overall there are clear insights on how they won the war
They had, and wantonly threw 10x the people the Germans had into the meatgrinder. It's not like it happened through some particular efficiency.
When I was 7 or 6 or something, I remember my granddad, who was in the Wehrmacht back then, very often explained to me how they fought during the war.
One of the things which stuck with me was how many more people the Russians had in comparison with the Germans. He once drew on paper to explain how they did something like cross fire where they would just fire with the machine guns so the lines of fire would cross and from down the hill Russians would run up the hill, die on the way up and new Russians would come up the hill without weapons and would take the weapons of the dead Russians and keep on running until they died, then another ones would take their weapons and so on.
I remember him saying it was 2000 Russian soldiers on one German soldier, but I guess that number got mangled through war propaganda, war reality, fear, and rumors on the front.
More broadly, the idea that they partied a lot - which is also one of the great story arcs in the book - does not detract from this. Think Wall Street, the Valley, etc.
Excuse me, but what you say goes 180 degrees contrary to account of every survivor, and popular public sentiment among the more erudite part of Russian society.
Just every member of political establishment at the time was portrayed as an idle hedonist of no intellectual acumen, but at the same very violent, and easy to snap. And this is the very reason why they gnawed each other to death in the thirties - no lard left, the society expired.
War confiscations, and ones in thirties were well known to end in coffers in mid-level officials, who themselves were a month away from starvation. That goes by account of every well respected person of that generation I knew in my childhood.
The myth of industrialisation is also just a myth. Russia had engineering school of its own, not much behind the German one, and a no joke industry by late ninetieth century. Just it was rather disperse, outdated, and suffering from disintegrated supply chain. Very low profile, and not earning headlines, unlike German one.
Year Axis troops Allies troops
1941 3,767,000 2,680,000
1943 3,933,000 6,724,000
1945 1,960,000 6,410,000
Casualties and losses
5.1 million dead 8.7–10 million dead
That is, to the German caught unawares, it looks as if there is an endless "Asiatic horde" (which was the fascist propaganda to explain losses), but what is actually happening is that the Soviets are successfully concentrating their forces by thinning them down where they aren't needed, and achieving greater numbers where they are needed. Good operational warfare that is, and the Soviets excelled at this. Also, a lot of the time the Germans were unaware of Soviet reserves, so that fresh forces would appear when they weren't expecting them.
The self-serving memories of Wehrmacht Generals mostly conveniently "forgot" about this, and so the myth of the endless Asiatic hordes was born.
There's a fascinating YouTube video  where House (Jonathan, not Hugh Laurie!) dismantles the three usual German alibis of why they were defeated:
1- Hitler interfered too much and was the cause of every blunder.
2- "General Winter".
3- "The Asiatic Horde".
The egregious waste of human life was ok because of advanced machinery?
the idea that they partied a lot - which is also one of the great story arcs in the book - does not detract from this. Think Wall Street, the Valley
I dunno, I did a fair bit of partying in Silicon Valley and I think the the fact that, however ill-advised and harmful, this didn't exterminate millions of people tends to detract from whatever 'this' is supposed to be quite a bit.
Again, the parent only explained that partying and hard work aren't mutually exclusive, not that this somehow makes Stalin's actions okay.
The explicit idea here is that Soviet success was a function of the exceptionally hard work of leadership.
They can, but one of these things endlessly colours the way we morally judge them. No amount of hard work makes up for a disregard for human life.
Maybe I'm misinterpreting it but this reads to me like 'the soviet leadership worked really hard and that won the war'.
You're just spouting bullshit written by the Germans after the war to justify their defeat.
If anything, I'd be spouting Soviet propaganda!