> Even if you take the Nazi propaganda that their laws were themselves lawful (which they were not, beginning with the clearly unlawful capture of power)
What definition of the laws lawfulness are you using? Capturing the power - it is what makes law lawful, otherwise any law is unlawful.
This is a very crude and on every level incorrect understanding on how laws work, both in a formalistic, as well as a societal way.
When the Nazis captured power, they did so by excluding the legitimate (and lawful) parliamentary opposition from key votes in parliament by (unlawfully) imprisoning opposition parliamentarians. In a strictly legal sense, this made their entire regime illegitimate from the outset.
What you fail to grasp is that a regime like Hitler's is constitutionally and ideologically incapable of being "lawful", i.e. having any set of laws and norms that would apply consistently, even if these laws were shaped by their own ideology. The whole point of Hitler's leadership was that laws were irrelevant and completely subservient to facilitating his twisted idea of Arian racial domination, with even the "German" society being completely dominated by the "Ubermenschen" that he hoped to create out of the murderous struggle of war.
Even the ancient Romans and Greeks would have recognized the Nazi regime as "unlawful". While the roman empire was a dictatorial regime, it had a mostly consistent set of laws and norms that even the Cesar had to abide by (though these laws gave him tremendous power in comparison to modern democratic executives). "Personalized" regimes in contrast are not build on laws, but revolve around the whims and/or ideology "the leader". You can see some aspects of this in Trump's approach to governance, though the US is obviously still a long way away from the extremes that the Third Reich went to.
What definition of the laws lawfulness are you using? Capturing the power - it is what makes law lawful, otherwise any law is unlawful.