Don't underestimate the addition of 360 more tanks (and as mentioned by others, the trucks, fuel, support vehicles, Anti-Tank units that go with them). It's easy to see the vast numbers of vehicles in WW2 -( 50,000 T34s? )- and think this is a drop in the ocean. However that's intergrating over a long time. And the numbers grew a lot more later in the war. Based on OTL and what was shipped to North Africa in 1941 alone , nevermind 1942 - the majority of those are top of the range Panzer IV - many of them F1 and probably some F2s - with a much more capable gun. Now would that have made a difference in July '44 - Hell no. Or even if spread out across the rest of the German army in 42 - little. But Allan has put them right where they are needed at the (second) tip of the German Spear.
To put that in context Bock - when faced with the surprise offensive of the Soviets in May 12th towards Kharkov out of the very salient these are being deployed to attack - had around 400 tanks total. That Soviet offensive failed and was probably always going to, although Timoshinko's ineptitude in commiting his main reserve for days after initial progress, doomed 250,000 Soviets.
So what Butterflies might we see? Most are in German's favour. Luftwaffe 2 has been withdrawn from the Med. Army group B gets it own Luftwaffe group. And whilst much smaller than Luft 4 that was diverted from Army A in the Caucasus to counter the Soviet offensive, it will not have had the same losses and crucially has substantial ground attack planes (still Stukas in '42). I'd expcet to see at a minimum the German's countering earlier and possible without the transfer of Luft 4. Which is a huge new butterfly for the South. Soviets lost all their armour OTL - but that was only 1200 tanks - to give you a sense of scale of almost doublig (and in the case of heavier PZr IVs - effectively more than doubling) the German response. You can't much improve much upon OTL for the Germans of completely wiping out 250,000 Soviets...but if it happens faster then they can get over the Donets sooner and really break out before any effective new defensives. This could really effect the starting points for Uranus later in the year or even cancel it all together. Even if timelines remain the same somehow, then Uranus is going to come up not against just Italian infantry and Romanians with Pzr 35s but much more capable Panzers.
History has focused on the inevitabilty of Soviet victory and what a turning point Stalingrad was. But if it's not the meat grinder - by Soviets not being able to get s many constant reinforements in, or Uranus not punching through the paperthin Axis reserves. It might hold.
More interesting is the oft underlooked south of the Caucasus of Army Group A. With more luft support, more fuel ( Rommel used multiple times as much per mile ) then what? Even if Maikop can't be captured earlier - maybe but it will still be wrecked - then actually destryong Baku would possible and WIN THE WAR for the Germans. Yep I said that. It wasn't Stalingrad that sent out the famous "not a step back" order from Stalin - it was , the OTL temporarily, cutting off of oil supplies from the Caucasus. Baku was just a bridge too far for the Luft 4th OTL but they did significinat damage despite the distance, closing in of winter and low fuel reserves. A few days earlier, forward bases a little closer, more fuel, not siphoning off so many aircraft earlier and suddenly - USSR doesn't have the fuel for those later huge operations. Yes they can get it from elsewhere - but not in the same volumes as quickly. 50,000 T-34s -- well they need a lot of Diesel. It matters a lot less that Germany is running out of fuel if the Soviets are too.
Only possible butterflies in Soviet advantage might be Tomoshinko commiting reserves earlier if he encounters heavier resistance in his attack. This probably won't change the outcome but may stall Paulus - an indecisive staff officer with no command experience whatsoever - even further. And lets not forget out hero - the Valiant tank. I'm sure ITTL the Germans are rolling out Pak 37 upgrades even faster but even so the Valiant had one thing the T-34 in '42 despertately lacked. Radios. Without the reserve advance units of Soviet tanks that made great progress in May 12th to May15h ' 42 were cut off in the German counter and command tanks were taken out as a priority as they were the only ones with Radios and easily identifiable. If the Soviets use their now shiny Valiant as front line tanks - sure it won't be the majority - but 100s in a force of 1200 + , then the soviets may escape the encircelement and have some clue about what is going on when the Germans counter in Mid-May. Or even just know what the hell is going, "Hey comrade , Boris just called from a Tank that smashed through German defences and this shit is actually working , lets pile in before the counter can come" Soviet attack will still fail but keeping a now experience 100,000 men east of the Donets is going to make Paulus's work in the summer harder. If Paulus panics (and he will - he really was awful) then instead of a Knight's cross for just being there at the 2nd Battle of Kharkov, he might withdraw. Germans really did lose their shit for the first 5 days or so of the attack after May12th.
But it's plausible that Germany can win the war from here. Or at least get Soviets to the table - Allies don't seem to be doing much and there will be no El Alamein to celebrate in later '42 - and have resources for a much tougher time for the Allies later I know it sounds ridiculous and that's probably not Allan's plan but effectively doubling Army Group B's armoured fighting strength (plus support) ... that is game changing
To put that in context Bock - when faced with the surprise offensive of the Soviets in May 12th towards Kharkov out of the very salient these are being deployed to attack - had around 400 tanks total. That Soviet offensive failed and was probably always going to, although Timoshinko's ineptitude in commiting his main reserve for days after initial progress, doomed 250,000 Soviets.
So what Butterflies might we see? Most are in German's favour. Luftwaffe 2 has been withdrawn from the Med. Army group B gets it own Luftwaffe group. And whilst much smaller than Luft 4 that was diverted from Army A in the Caucasus to counter the Soviet offensive, it will not have had the same losses and crucially has substantial ground attack planes (still Stukas in '42). I'd expcet to see at a minimum the German's countering earlier and possible without the transfer of Luft 4. Which is a huge new butterfly for the South. Soviets lost all their armour OTL - but that was only 1200 tanks - to give you a sense of scale of almost doublig (and in the case of heavier PZr IVs - effectively more than doubling) the German response. You can't much improve much upon OTL for the Germans of completely wiping out 250,000 Soviets...but if it happens faster then they can get over the Donets sooner and really break out before any effective new defensives. This could really effect the starting points for Uranus later in the year or even cancel it all together. Even if timelines remain the same somehow, then Uranus is going to come up not against just Italian infantry and Romanians with Pzr 35s but much more capable Panzers.
History has focused on the inevitabilty of Soviet victory and what a turning point Stalingrad was. But if it's not the meat grinder - by Soviets not being able to get s many constant reinforements in, or Uranus not punching through the paperthin Axis reserves. It might hold.
More interesting is the oft underlooked south of the Caucasus of Army Group A. With more luft support, more fuel ( Rommel used multiple times as much per mile ) then what? Even if Maikop can't be captured earlier - maybe but it will still be wrecked - then actually destryong Baku would possible and WIN THE WAR for the Germans. Yep I said that. It wasn't Stalingrad that sent out the famous "not a step back" order from Stalin - it was , the OTL temporarily, cutting off of oil supplies from the Caucasus. Baku was just a bridge too far for the Luft 4th OTL but they did significinat damage despite the distance, closing in of winter and low fuel reserves. A few days earlier, forward bases a little closer, more fuel, not siphoning off so many aircraft earlier and suddenly - USSR doesn't have the fuel for those later huge operations. Yes they can get it from elsewhere - but not in the same volumes as quickly. 50,000 T-34s -- well they need a lot of Diesel. It matters a lot less that Germany is running out of fuel if the Soviets are too.
Only possible butterflies in Soviet advantage might be Tomoshinko commiting reserves earlier if he encounters heavier resistance in his attack. This probably won't change the outcome but may stall Paulus - an indecisive staff officer with no command experience whatsoever - even further. And lets not forget out hero - the Valiant tank. I'm sure ITTL the Germans are rolling out Pak 37 upgrades even faster but even so the Valiant had one thing the T-34 in '42 despertately lacked. Radios. Without the reserve advance units of Soviet tanks that made great progress in May 12th to May15h ' 42 were cut off in the German counter and command tanks were taken out as a priority as they were the only ones with Radios and easily identifiable. If the Soviets use their now shiny Valiant as front line tanks - sure it won't be the majority - but 100s in a force of 1200 + , then the soviets may escape the encircelement and have some clue about what is going on when the Germans counter in Mid-May. Or even just know what the hell is going, "Hey comrade , Boris just called from a Tank that smashed through German defences and this shit is actually working , lets pile in before the counter can come" Soviet attack will still fail but keeping a now experience 100,000 men east of the Donets is going to make Paulus's work in the summer harder. If Paulus panics (and he will - he really was awful) then instead of a Knight's cross for just being there at the 2nd Battle of Kharkov, he might withdraw. Germans really did lose their shit for the first 5 days or so of the attack after May12th.
But it's plausible that Germany can win the war from here. Or at least get Soviets to the table - Allies don't seem to be doing much and there will be no El Alamein to celebrate in later '42 - and have resources for a much tougher time for the Allies later I know it sounds ridiculous and that's probably not Allan's plan but effectively doubling Army Group B's armoured fighting strength (plus support) ... that is game changing