"Given that present day Aryan individuals frequently are the only one in their entire known family"
I was referring to situations where one would be more likely to find Aryan blood in their extended family, for example if one belonged to a vegetarian clan, one could expect to find Aryan blood as the descendants would at the very least be adhering to a noble lifestyle.
However, even here the inferior descendants would be able to mask their ignobility as it is possible they are merely adopting vegetarianism out of social pressure. In this case, it is better for such individuals to not reproduce. One of my cousins, for example, despite belonging to the same vegetarian clan as myself, regularly consumes meat and has even taken up hunting! However, it is only because he is unmarried that he pursues these activities openly, whereas if he were married, his ignoble blood would stealthily be passed on as he could pretend to be noble merely for social purposes.
Hence, with the removal of the social pressure to reproduce in order to "save the clan", my ignoble cousin has effectively been weeded out from the gene pool.
"Hypothetically, if the only other Aryan individual you know happens to be your cousin, then of course it is better to reproduce (if at all) with your cousin rather than with someone inferior. "
Ok, but what about the possibility of genetic defects? Do you agree with the Western medical analysis that reproducing with a cousin is more likely to cause genetic defects in the offspring?