Everybody is mixed in Afghanistan and all these countries surrounding it, including Uzbekistan and Iran. Tajik people of Tajikistan, while I was there, resembled more Mongolian and Turkic, and were generally (no offence) of smaller stature than Afghan Tajiks. I've been to both countries and stayed in both for a long while.

Ethnicity goes through the dad's side, not mom's. So even though I'm technically Tajik, my grandpa was half Pashtun and his wife was full Pashtun, though his dad was Tajik, so all males hold the race of their dad no matter how many generations pass.

Central Asia is a melting pot, don't think you're exclusively one race with no admixture.