I think that might be tricky to do as it is a subject which might be a bit too complex for an allegory. Not that allegories are all that good to begin with (I am looking at you, TNG).
Genesis of the Daleks is not good because the Kaleds are thinly-veiled nazis. No, it is good precisely because the Kaleds are not only nazis, there is e.g. also some Frankenstein in it. And although Davros is of course very fascistoid there is no obvious real-world historical equivalent of him:
Most top nazis were not outstandingly smart whereas Davros is a genius. Most top nazis were aware that their ideology is a big lie but believed, Orwellian double-think style, in it at the same time whereas Davros naively believes in his Daleks.
Fascism did feature some of this racist / eugenic purification stuff and this totalitarian monistic evil ("one people, one nation, one leader") whereas in Genesis we have a more radical form of it.
So Genesis of the Dalek works because it is on the one hand more fascist than real fascism and because it is about more than just that. You could say that it starts with an object, makes it more radical and in the process takes all kinds of other objects in. The last step is crucial as it is absent in an allegory which is limited by its subject (I intentionally used the word object before, you could e.g. say that nazism is the subject of Genesis but at the same time it transcends its subject or Frankenstein becomes its second subject so why not claim that these are rather objects, ingredients for a good story?).
I guess that all that WWIII / Eugenic Wars background stuff in Trek also works precisely so well because it is not an allegory of eugenics in the early 20th century but more general than that. With biogenetics becoming more and more possible/powerful Trek's discussion of the issue is thus ironically becoming more actual than it was back in the days.