Ahh yes, bringing German scientists and technical staff to the USSR to learn from them and then repatriating them back to the GDR 5 years later is exactly the same as putting an SS Sturmbanfuhrer who was personally in command of a facility where slave labor was worked to death into leading roles in your space program into the 1970s.

Let's also just conveniently ignore the fact that the R-2 rocket was developed by Korolev's team in direct competition with the G-1 rocket developed by a German team working in the USSR. The USSR chose the R-2 over the G-1 specifically because it didn't want the Soviet space program being led by Germans and by 1950 had repatriated most of the German specialists.

After 1950 the Soviet program was largely indigenous, led by Korolev and other Soviet citizens. All of the major achievements of the Soviet program were led by Soviet citizens, scientists and workers.

The entire V-2 team under von Braun from Peenemunde surrendered to the Americans on May 2, 1945 and brought with them more than 400 core scientific-technical employees, full documentation and reports and more than 100 intact copies of the A4/V-2 rockets ready to be shipped to the front, together with the combat launchers and the military personnel trained to operate the missiles.

The Peenemunde site was by then already deliberately destroyed to prevent anything useful from falling into the Soviet hands.

Operation “Ost” did happen, however, but the highest ranked German scientist they managed to recruit was Helmut Grottrup, who was von Braun’s deputy for missile radio-control and for electrical systems. He had claimed to be an anti-fascist, we may never know the truth, but he was indeed imprisoned by the Nazis for a time.

The vast majority of the German specialists who worked for the Soviets were not former associates of von Braun in Peenemunde, but were instead introduced to rocket technology when the Soviets established the Institutes RABE and Nordhausen in Germany after winning the war.

Werner von Braun later remarked:

“… the USSR nevertheless succeeded in acquiring the chief electronics specialist Helmut Gröttrup… But he was the only important catch from among the Peenemünde specialists.”

Other German scientists who worked for the Soviets such as Kurt Magnus and Hans Hoch (leading academics in gyroscopy) as well as Manfred von Ardenne (later awarded Hero of Socialist Labor) came from the academia and adjacent industries, and were not members of the Nazi Party.

They also managed to recruit workers and technicians who were POWs liberated from the Dora concentration camp (which supplied personnel for the notorious Mittelwerk factory, where von Braun had committed crimes against humanity including the torture, beatings and execution of the prison labor). Many of the POWs were involved in the sabotage of the A4 (V-2) rocket production at Mittelwerk, and resulting in substantial proportion of misfires and inaccurate flight trajectory when the Nazis used the rockets against England.

In other words, the Soviets had to reverse engineer pretty much everything from scratch (the R-1, which is the copy of A4/V-2), while the Americans got everything they needed. The Americans only fired the V-2 a few times, and then went on with their own “hybrid” designs such as the Navaho, Aerobee and Viking.

And in spite of all this, with such overwhelming advantage, the Americans still LOST the race against the USSR. The R-7 became the world’s first ICBM to be launched in 1957.

To put it in the terminology of you computer nerds, the Americans got the entire core dev team, with the complete source code and full documentations, and the whole tech support team, while the Soviets had to work with and piece together information from third party developers, and still raced ahead of the Americans.