Afghanistan would not be included in either definition. Someone of Afghanistan ancestry (I'm purposefully avoiding distinguishing the various ethnicities in Afghanistan) would be classified as either Middle Eastern or Caucasian under the census definition as well as in the vernacular.
It's as far from a small homogeneous group you can get.
So how would you group them? People from the Middle East at least share a common religion, even with many North Africans, and are arguably a significant subgroup of "Asians" overall, but the average Indian is a lot closer to the average East Asian individual in general. Buddhist ideas are stemmed from Indian religious ideas, and plenty of shared cultural beliefs exist.
https://locusmag.com/2016/03/cory-doctorow-wealth-inequality...