It's called the dual state, it at least on the context of the Nazi state in Germany.
The Nazis as you correctly pointed out mostly left the regular administrative state working. And added a second pillar "extra constitutional" based on the leader who could basically decree whatever he wanted and break the regular rule of law.
Or libertarian friends are about to find out what the Allies found out after WWII: you cannot run a state without the adminstrators.
Cory Doctorow (npub1fdr…lvhs)