Muslim. Therefore unlikely for even a non-devout Sikh..
I never said it was
exclusive to Muslims or that it was a religious practice in itself. I was using its prevalence in Muslim communities as an
example to illustrate the fact that its use is not rigidly constrained to any one community or practice. It may have originated with Central Asian nomads, but their conquests and cultural influence spread across Eurasia and the ripples of it propagated far beyond them. My point is that the name is used widely enough that it's unrealistic to insist it
can't be used in a certain way.
Besides, the Augments were supposedly multiethnic and multicultural. One can presume that, if they were born and raised together, they were raised with a mix of cultural influences. Insisting on a rigid, inflexible interpretation of cultural practices seems unreasonable in this context.
But if Khan is supposed to be his family name, then he would be Noonien Singh Khan, not Khan Noonien Singh.
Not necessarily. As I understand it, a Sikh's surname is usually their second name, with the Khalsa name (Singh for a man or Kaur for a woman) appended after it, though it can be the other way around. The Khalsa name is more like a title representing their baptism in the faith. So it would be Noonien Khan Singh,
if Khan were his surname. Again, though, just because it's
commonly a surname doesn't make it impossible for it to be a given name. Sikhs don't necessarily even use surnames the way Westerners do, so adopting a second (or third) name doesn't follow any rigid rule.