You are heavily overstating the case; NATO studied German operations for their planning after the war for operations against the Soviets in Europe.
I'm not and I'm referring to NATO staff colleges today, not during the Cold War. For much of the Cold War NATO did indeed study German operations (which was foolish, given that these operations had failed to defeat the USSR or even stop their later offensives) and dismissed Soviet concepts of Operational Art as an artificial insertion they added between tactics and strategy. Only after Vietnam did this start to change, if slowly. The first time operations were discussed as a distinct doctrinal entity by the US Army was in 1986. Desert Storm opened a lot of eyes and NATO states quite abruptly certainly changed their tune, but it still hasn't quite caught up even today.
From WWII to Vietnam, the overwhelming Western doctrinal focus was on tactics, at which they were
very good. Even in NATO's modern operational art they are still quite tactically focused, and their operations are a sum of various bits and pieces rather than a (theoretical) seamless doctrinal whole. NATO is doubtless better in operational
practice than the Russians today, just from experience, but Russians still have a greater wealth of operational
theory than NATO does, and I'd bet they still spend more effort on discussing and debating it than NATO does.
As an interesting aside, probably the services who were closest to Soviet operational thinking were the US and Royal Navies. Like the Red Army, both faced huge challenges of fighting a powerful enemy across vast distances, and developed operational theories prior to WWII that were successfully modified and matched to war practice. They didn't articulate the concept of "operational art" as clearly as the Soviets did, but the exact same kind of thinking was all over their strategic warplans.
Also what does that have to do with the specific situation in Hungary in November 1944?
It's me lampooning your continued assumption that the late-war Soviets did not have the best Operational Art out of all the combatants by noting how even the modern US, British, and even
German military disagrees with that.
Less irrelevantly, the Soviets by 1944-45 had achieved such a level of operational practice that they quite well understood how the Germans operated as well as how they themselves operated (
know thy enemy and know thyself). They would know quite well what a major German offensive entailed, what steps would need to be taken to stop this German offensive, and they would move to implement them as rapidly as possible regardless of whatever cost in lives and material (replacements of both of which they had in copious amounts anyways) this would require. They would know to improvise a series of hasty anti-tank defenses behind the area the Germans threatened to breakthrough that would slow and bleed the German spearheads while assembling their mobile forces to strike through the German advance's flanks (which would by necessity have to be held by the pathetically weak volksgrenadier formations) and threaten the spearheads with either abandoning the advance or being encircled. Like so...
Of course, this all assumes the Germans achieve surprise, which is far from guaranteed
They had topped out on their advance
Which is why they almost immediately then proceeded to advance further!
and they had a wide flank to the south
Which was anchored on the solid terrain feature that was the Danube river.
while drawing supply across the Carpathians;
Which was proving quite adequate for the sustainment of offensive operations.
they only advanced that far and fast due to Romania switching sides and the Germans have no forces present to resist them;
And the Romanians switched side because their (and the Germans) forces had either been annihilated or were about to be and there was nothing to stop the Soviets from crossing their entire country anyways.
when they met resistance their advance slowed to a crawl in November.
Such a crawl that they had advanced clean across Eastern Hungary by the end of it and were in the process of breaching the Danube.
They breached at least two lines and inflicted over 3:1 losses on the most heavily prepared defensive zone the Soviets ever managed to muster that took months to build up.
Which amounted to all of a dent. They failed to even get a third of the way through. As far as offensives go, that is a poor showing. And the casualty rate again proved irrelevant as the Soviets near-instantly replaced all of their losses.
In November 1944 they are at the end of their supply lines,
Given that they continued to supply their forces just fine through the advances that immediately followed, clearly not.
Actually, given the later developments (see below), the Danube river by late-November is pretty clearly 3rd Ukrainians Font's... well, front
have had no time to build up defenses,
half-to-one full month is plenty of time to erect a basic defensive network.
and have been slowed to a crawl by minimal Axis forces in the area.
If by "slowed to a crawl" you mean "relentlessly advancing across the Hungarian Plain" then sure.
Okay, again limited Axis defenses, then proceeded to get bloodied by German forces that were badly outnumbered that began filtering in.
And they continued to advance and defeat those German forces.
The Soviets aren't holding the river with huge forces in November, they just got there.
They had not "just gotten there". In some places they have been there since early-October, in others since mid-November. It depends on how far north you go up the line.
That is not in early nor mid November:
Correct! It is mid/late November!
Roughly.
They went from overrunning Romania and their Carpathians in August to October to taking nearly two months to encircle the city.
One month actually. As your own maps up there somewhat illustrate, November was spent pushing across the Hungarian plain. On November 26th, they began the first stage of the Budapest encirclement. South of Budapest this consisted of the 3rd Ukrainian Front forcing the Danube and clearing the Germans from the southern and eastern banks of Lake Balaton by December 9th while 2nd Ukrainian Front fought its way across the Borszony Hills to the north. The second stage was a coordinated offensive between the 3rd and 2nd Ukrainian Fronts launched on December 20th, with the link-up occurring just north of Esztergom. The first Soviet troops, a reconnaissance detachment, entered Budapest proper on December 24th from the west. There is an amusing story about how they were able to ride one of the cities tram cars to the utter astonishment of the various Christmas shoppers. The citizens of the city itself were caught by surprise by the whole thing, which is really weird when you consider how long the fighting had moved into Hungary.