According to:
https://www.macalester.edu/~hammarbe.../Whoiswho.html
It may just be multiple last names and same person:
Quote:
Kuragin family:
Prince Vasili Sergeevich Kuragin
|
I am not familiar with naming convention, but looking through that list makes it appear that the one last name "Sergeevich" is in a spot that refers to one's ancestors family.