According to Otto Chaney ("Zhukov") one of the briefing sessions given by Zhukov and Vasilevski (the principal architects of "Uranus") on November 13. At that briefing, attended by Stalin, "Zhukov and Vasilevski advised that it was expected that the 6A would attempt a breakout and the germans would amass as much of the locally available forces as possible to effect a breakout. This was expected and anticipated, and in some regards was greeted with some relish as fully 40% of available forces were to be kep back to cover such an eventuality. An attempted breakout by 6A would, in the opinion of Zhukov only serve to expedite the demise of that army, as operations would transform from a static battle to a mobile situation.
It was expected that the Germans would transfer part of their r4eserves fro around Vyazama to form a relief force for the southern group of armies. Though sufficient reserves were ready for such an eventuality, It was agreed that to prevent or diminish such reinforcement, the Soviet Kalinin and Western Fronts….'
Zhukov stated" the Stalingrad operation, in all respects, and for all eventualities is adaptable and ready for all reasonable eventualities that the Germans are capable (of )…
Stalin was in full agreement, and very happy with the preparation report. But he gave the following instructions "Fly to Stalingrad tomorrow. Check one more time on the readiness preparations".
Zhukov did this, and as expected was satisfied. There were no major changes, though the commander of the lead 4th Mech Corps did write a letter expressing his concerns about the offensive. This letter was shown to Stalin, who was so confident in the operation, that no changes were proposed. Volsky kept his life and his job, despite his public concerns. He was later decorated for his role in the operation.
On the conduct of the offensive operations themselves, Chaney makes a number of illuminating observations.
"On the morning of November 19, soviet artillery began to Soviet offensive. The attacks were led by elements of the SW and Don Fronts (committed to the offensive at this stage were 18 Inf Divs, 8 tank Brigades , 2 Mech Brigades, and 9 Cav Divs supported by at least 10 Artillery Divs.; In reserve were more than 60 Divs). Just before 9am, the supporting artillery shifted to deep targets and the assaults began. SW Front, led the attack and penetrated the defences of Rumanian 3A in 2 places, virtually destroying two divisions at the critical point of breakthrough before lunch.
By days end, the Rumanian 3A sector almost in its entirety was in deep crisis and Soviet breakthrough formations were clear of the front area and quickly on the move. The attacks were so swift and so successful that only three of the 18 divisions were needed for mop up operations. In the meantime, Major generals Rodin's 26 tank Corps broke through at Perelazovski, inflicting a huge defeat on the Rumanian 53 Corps. Once Perelazovski had been captured 26 corps wheeled south to link up with elements of the Stalingrad Front which were exploiting the outstanding breakthroughs and allowing the lead assault elements a short respite. The next day the first significant German elements were soundly defeated as they attempted a counterattack. In a bold move, 26th Corps, took advantage of darkness to seize a vital bridge across the Don, intact, near Kalach. The germans mistook the Soviet flying column as their own, local commanders having completely under-estimated Soviet grasp of mobile operations. The Soviets crossed this vital bridge unopposed, consolidated, fanned out and signalled for the remainder of the main force to cross. The Germans retreated in complete disarray, and with heavy losses.
21st Army having ripped into Rumanian 13th and 15th Divs at the frontier, sent its mobiles groups (consisting of 4th Mech and 3rd Gds Cav XXX, poured through the hole that had been formed and exploit the penetrations that had been made. – 'just as as we had taught them to do" wrote Manstein. In co-ordionation with 5th Tank Army, the breakthrough group was ordered to destroy the gathering enemy (German) reserves HQ and rear area units, cut off their withdrawal routes to the west and southwest and block the routes of the expected deep reserves. By 22 November, the Group was to link with the Stalingrad front near Sovetski, SE of Kalach, and from there o await further orders.
On 23 November 4th mech spearheaded an increased tempop of operations by leading a further assault against further gathering of german reserves readying for counterattack. Soviet reserves were now puring into the salient in anticipation of an expected 6A breakout attempt, and/or German attempted break in. The Soviet high command was determined that such attempts would fail. 26th corps attacked the Germans at Kmayshin, who were prepring for a counterattack, and defeated them heavily. In four days the Soviets had closed the ring and heavily reinforced their positions. They were ready and able to meet any possible German reaction to the encirclement, such that such attempts at relief were likely to fail.
Stavkha fully expected the germans to mount some form of counterattack, and had organised their forces and their reserves to meet such an eventuality. Mansteins assessment was that in the critical days of late November the Soviets had the strength, the training and the organization to defeat the entire Army Group A. and 6A with a quick thrust to Rostov."
I would suggest that the reason that the Soviets did not unleash this additional offensive until 16 December was firstly because 6A remained in place and resisting, and secondly for four days after December 12, they had to contain and defeat the German break in attempts.
I fail to see how, on the basis of the above, anyone can seriously argue that breakout, or break in attempt(s) could have any real chance of success. The Soviets were too well prepared, too numerous, and too well deployed and led to be defeated in this operation. A breakout attempt was what they expected, and wanted. If it had been attempted, it would have been a disaster for the whole of AGS