do you mean the initial winter offensive in Dec 41, that pushed the German's back or the follow up ones Mid Jan 42 onwards that saw increasingly diminishing returns for expended losses?
Either way I think you have to judge the results of both in teh context of the time. Frankly at this point large Soviet losses is just a given, the big story here iss that not only is the Red army capable of mounting a counter offensive after fighting ths German for 6 months and suffering millions of looses but that they actually pushed the Germans back.
Remember the German mindset and thus he entire plan for Barbarossa and the invasion of Russia in general is built on 2 key assumptions:
1). The Red army will not be able to resist the German advance enough to stop it
2). The red army will be quickly reduced by inflicted looses beyond any ability to mount any significant further resistance.
Importantly key things like resource allocation, long term goals and logistics were based on these in key ways.
You wont need huge resources because all the serious fighting will be done in 3 months
Long logistics chains won't be problem because they'll be run through compliant and docile occupied territory replete with intact transport infrastructure and since you'll just be mopping up you won't need that much anyway since the fighting won't be fierce and you won't be suffering losses
You will be seizing all those luverly soviet resources anyway, in fact we expect to see teh flow of resources to be the other way, etc, etc
Those underlying key tenets impact pretty much everything that happens 1941 onwards, and even if some German commanders begin to realise the problem it doesn't really matter because teh entire campaign was planned and run based on them and thus they're already locked into their mistakes.
The Winter counter offensive basically further underlines that these key tenets of German thought were wrong, and thus those aspects of the campaign tied to them are really going to unravel e.g. logistics and resources. Now don't get me wrong Stalin gets cocky mid Jan 42 onwards and loses forces he didn't need to in further offensives that achieve little, and that in turn makes teh German renewed offensive easier.
The above is important for the two things you bring up
Stalingrad first and then the caucuses. and not trying to pocket large number of Soviet troops. Only its pretty much has the same issue as the idea of just drive to Moscow ignore everything else in 1941.
1). The plan was still destroy the red army so they can't resist so no they're not going to ignore pocketing the red army (in terms of Germany beating the red army the Germans greatest successes came from doing this their not going to not do it now).
2). Logistically Germany is going to struggle to support a quicker thrust to Stalingrad (you have to wait for teh roads as well) , especially as going for Stalingrad risk your thrusts flanks. As per above the red army has now been shown to mount counter offensives of increasing effectiveness compared to last year, and the article you linked to makes the point the Caucuses aren't empty of Soviet troops. I,e you can't ignore everything but Stalingrad but that doesn't mean everything will ignore you. I,e. Red red army general crapiness and ability to respond early on does mean the Germans can to an extant go where they want, when they want. But that become less and less true towards the end of 1941, during the winter of 1941/42 and then on into 1942. (not just because the Red army gets better because that's a slower progression, but also because the German forces degrade due to loses, supply and requirements of having to hold down teh vast amount of territory they had occupied)
3). Germany wants the caucuses firstly to deny them the enemy and secondly for it's own needs, you can't ignore that
4). it's all still based on this idea that reaching certain points on a map and the USSR will curl up and die
Ultimately its the same old problem, I can see why it's tempting to concentrate limited resources and logistics for single pushes and knock out blows, but these single pushes still have to operate within a larger context of invading a massive and still actively resisting country and resource demands from back home. The German forces are being pulled in too many directions at once.
Bombing Baku, yes in theory it possible in that August window (or before if they don't try to occupy the fields at all). but again a few points.
1). bombing campaigns against oilfield's did not have great history of actually long-term stopping production, (but the fear of it also drives the German attacks on Crimea) especially here as:
2). the LW itself was operating at the end of a long supply chain. In fact most LW bombing campaigns against Russian key resources tended to follow the same pattern a few relatively small in size attacks that inflict damage that is quickly made good, because they couldn't run long ongoing campaigns to keep the damage going. why can't they do this? because the LW has the same issue as the rest of the German forces, namely too many targets and increasingly effective resistance.
3). It involved redirecting LW assets from the Stalingrad attack, this would have had implication for that attack OTL and for your idea above. Especially as as per point 2 this won't be temporally diverting planes in the area for just one quick raid then back to Stalingrad, but to be effective a long ongoing bombing campaign.
3). The Germans need that oil production. We know they were unlikely to get much in time, even if they did take the fields, but that doesn't change the fact they needed it and will try
4). The premise in the article is of the Germans attacking towards the oil fields in June, realising they can't get it by early enough in Aug to then have time to decide to flatten and muster the forces to actually do it within Aug. That requires an amount of self realisation and changing of gears on the Germans part that frankly they had displayed to a stunning lack of in Russia up until then, I find it hard to believe this will be the moment they develop it
5). The soviets are just going to let it happen, no adjustment to their OTL?
In summery there is I think a belief that for Germany to change it's fate in Russia it just has to reverse specific results, e.g. getting to Moscow in 1941, keeping Stalingrad in 1942 etc, but this supposes that not only where these the only things that stopped the Germans from winning (or not losing as time goes on), but that these OTL results are the only ways the Germans can lose in Russia.
Stalingrad is a interesting one because we tend to hold it up as the iconic moment when "it all changes", and while it's a good deal more complicated than that I can kind of see why we do it. But it more whet teh end result of Stalingrad signifies in terms of the changing situation in the east that matters. Not Stalingrad in abstract. I.e. the end result of Stalingrad is because the situation had changed, Stalingrad didn't cause the situation to change.