Unsure how many other people there that are similar to Nazis, can only think of the Boltons right now  (at least before Danerys took control of  the seven kingdoms). They're usually accused of causing problems but they're actually quite poor in judgement, so not even they can compare to a once highly successful group with the main goal of not simply surviving,  but to infiltrate and take over, to exploit others in the most devious, parasitic way.