I ask because the idea of a race of "full blooded Aryans" basically sounds to me like a bunch of inbreeding. So like say the Nazis did win WW2, what was their plan to avoid becoming a physically/mentally disabled and sterile nation of sister-cousins and brother-uncles 25, 50, 100 years down the road?
Did they think there would be any room for procreating with the people in the lands they had conquered or was it all "We kill them all and then populate the land with pure Aryans" without thinking too much about it?
In my mind it's just common sense that it wouldn't work out well for them, so why didn't they see it?
Please do not call "appalling ignorance about how the world works" common sense. If inbreeding was that severe, humanity would have gone extinct long ago, since of course throughout history the vast majority of relationships were within the same ethnic group and in the vast majority of these with people within the same settlement or those in the immediate vicinity. It's not exactly clear how big a population group would have to be to avoid dying out due to the harmful effects of interbreeding, but
5000 is probably the largest reasonable estimate.
