Well Nazis had like ~30% support in Germany so that's probably enough to monitor the remaining 70% (1 person to monitor ~2 others)

However, if your regime is even smaller like 5% or 10% it's going to be extremely difficult to manage the remaining 95% without more advanced technology than pen and paper.

There is more to it than that.

The notorious example is the Dutch Jews who basically filled in a register of themselves and provided it to the Nazis.

I tried to watch Joodse Raad and I just can't.

Yet, they killed the Jews in occupied countries as well. Shockingly, the Nazis were the least efficient at doing their genocide at home where the support was highest.

Not that surprising. They needed slaves to build their war machine and you want these factories far from the front.

I think it's inverted: their support was highest where they weren't doing the worst things.

I'm not sure that's accurate. By sheer numbers, it's pretty much Poland taking the lead and that's because the rest of Europe killed/displaced their jews in previous events (turns out hating jews is basically an European tradition).

Statista agrees you with in that comparing the deaths by country to its initial population by country shows Germany around 32% while say Poland is 75% [1]. But the big problem with that is it omits emigration; I would suspect jews in Germany saw the writing on the wall and left. The Germany jewish population dropped from 525k to 37k [2] (with 165k dead [1]) which means 323k jews must've left Germany while Hungary dropped from 445k to 190k (with 270k dead) which means -25k jews emigrated (aka 25k jews immigrated).

So it just appears that Germany is less efficient because the local jews emigrated to other countries where they were then killed juicing those countries stats.

[1]: https://www.statista.com/statistics/1070564/jewish-populatio...

[2]: https://encyclopedia.ushmm.org/content/en/article/remaining-...