They were very far away.

Kursk, as you mentioned, was a massive battle on a large scale. The sky was as crowded as the ground with tanks and soldiers fighting it out. But history has been too kind to the Germans in my opinion and a current thought by many historians is that Germany was about to win if only hitler hadn’t pulled the troops out. This though a very big lie.

The German attack was launching north and south and trying to encircle the Soviet troops at Kursk. Their were definitely some successes in some areas but the Germans were practically walking into a wall. The Soviets had not only been told by British code breakers where the attack was going to take place but the Soviets has known for some time, and they had fortified the Kursk area with every weapon from anti tank guns to machine guns and artillery. They had actually known what time the Germans were going to attack and fired artillery upon them before the Germans were even able to start their battle. German tanks such as the Panthers and Tigers, new but powerful, were breaking down constantly ( more so with the panthers as the tigers have been out for some time ) and the air was constantly contested and soviet fighter bombers were very good at knocking out enemy forces. Only through aggressive German actions and near suicidal attacks were the Germans able to take any ground. And this ground was taken and lost over and over in some areas. This went on for nearly 13 days and nights. It was a slugging match and that’s what the Soviets wanted. Germany was lacking oil, steel and rubber among half a dozen other extremely important resources. The Soviets wanted to get the Germans into a match where they could slowly destroy them and they managed to do just that. So eventually the Germans called off the attack. Partly because of allied troops in Italy but partly because they didn’t think continued attacks were going to work, which they were right.

The Soviet doctrine dictates constant attack. Attacking gives the attacker control of which engagements are fought and makes the enemy have to respond. It’s even stressed to counter attack right as the enemy launches their attack. The meta of Kursk ends when German troops stopped their attack, but the Soviets had build up their forces in surrounding areas near Kursk and attacked themselves around this time. They broke through the German lines in some areas and German forces were forced back. Not only did Germany fail to take their objectives, they lost territory as well, ever inching them back to the fatherland.

In reality. Germany was not going to take any operational objectives. And they were no where close to it. British intelligence, Soviet defenses, aggressive behavior, air, tank and infantry stopped the Germans dead in their tracks. The Germans were able to gain some ground but only at huge cost. The Soviet reserves were ready to meet any losses the Soviets faced where the Germans didn’t have that luxury. So I’d say this, what little gains the Germans did make are a miracle in their own.

Germany didn't come particularly close to achieving most of their tactical goals for the Kursk, let alone operational. They failed, in all sectors, to achieve breakthrough of the tactical defensive belts, although XLVIII Panzer Corps did nearly get through the tactical defenses in the vicinity of Oboyan. However, they ran headfirst into Vatutin's reserves in any case - this of course being the Prokhorovka engagement. Had they decisively defeated Vatutin's reserves in an encounter battle and somehow retained enough combat power to hold that gap in the Soviet defenses while reinforcements could be brought forward, the Germans would then have had to contend with the Soviet operational reserve in the form of Konev's fresh Steppe Front. There was a more basic problem, though. As the northern portion of the offensive had stalled out almost entirely - my recollection is that Army Group Centre never penetrated the second defensive belts anywhere along their axis of advance, I have to double-check Glantz & House's Kursk book to confirm - the German concept of operations had already been decoupled from events on the ground. Without Model's northern forces breaking through and linking up with the southern spearhead, the ambitious plan to encircle and defeat the Soviet forces in the salient in detail was no longer feasible.

It is certainly possible that Hoth and Kempf's forces in the south could have fought their way to a larger hole in the Soviet lines, possibly disjointing 40th Army and 6th Guards Army from each other entirely and creating a stable enough rupture to inject the exploitation forces. However, these forces would still have run smack into the Voronezh Front's operational defensive lines, some 20 miles from the furthest extent of XLVIII Pz Corps' advance. And, again, they would have been faced with both the remainder of Voronezh Front's operational reserves and some portion of Steppe Front's reserves aggressively attempting to close the penetration in the lines & destroy the German spearhead. Even the most aggressive, dogged mobile exploitation force, had it survived the Soviet attempts to contain it, would have found itself racing ahead to nowhere. There was no real possibility for the grand Kesselschlacht by this point in the hypothetical alternate timeline, and the best that Army Group South could have likely achieved on its own here would have been an encirclement of one or two armies, effectively carving out and destroying one chunk of the salient. It is exceedingly rare to find cases in military history where an outcome seems almost impossible, but I think in this case Glantz & House's summary in When Titans Clashed has the right of it: "In a very real sense, therefore, it was physically impossible for Operation Citadel to ever create the penetration necessary for a true blitzkrieg exploitation."