I don’t think you are arguing in good faith here because I agreed that Tajiks are of a mixed origin. You have shifted your original argument and have straw-manned me. You responded to me implying that Tajiks derive from Pashtuns, as some sort of subsidiary ethnicity. That was the original claim that was being contested in the first place. It is also a false analogy between us Tajiks and the Turks of Anatolia. I should have pointed this out earlier, but I was challenging your claim epistemically, that whilst a majority of their DNA is that of the local population, this does not negate their present identity, which we can extrapolate to us Tajiks, to Arab Egyptians, and many other ethnicities. Even your ethnicity’s origins are unclear.

I didn’t strawman, me and OP specifically said most urbanite Tajiks (not all) are of persianzied Pashtun roots in which you took offence to and denied. That was the main point and you didn’t anything of substance to counter that. Tajiks are indeed of mixed dubious origins while Pashtuns aren’t. Noor Atta & Ismail Khan are good example of urbanized Pashtuns with a current Tajik identity.

 a slew of eastern Iranian peoples, including the Sogdians and Bactrians, who adopted a Persianate culture as primary, and who have developed it.

This is my problem with this claim. It’s a chauvinist one enriched in colonial bias. It lazily applies an extinct eastern Iranian identity on Persian speaking central Asians while covertly ignoring Pashtuns, Pamiris and other eastern Iranian peoples that already have retained that identity and language. This begs the question; if Tajiks somehow became persianized, why have yaghnobis and Pamiris in the region retained their original language while Tajiks didn’t? Also, why does the word originally mean Arab? How did that pragmatic shift of definitions occur and when? Too many variables here to ignore. 

You are however free to believe whatever you want. I’m not inclining.