[Semiapies]

There was no Nazi economic miracle

https://en.wikipedia.org/wiki/Scare_quotes

As far as that, I don't see how hiring foreign advisors somehow make your own economic achievements worthless

Because there were no "own economic achievements" in this case. The USSR claimed to pioneer a new and superior economic system to the capitalist West, but their greatest period of growth and improvement was accomplished through Western direction.

[sudosysgen]

It wasn't through Western direction - they did not implement free capital market, which was the "Western direction".

They imported technical experts from the West to help them design and build things until they figured out how to do it themselves. That is orthogonal to the economic system.