Definition wise, sigmas are very good socially. Not introverted or autistic. 
The difference in male types is in Goals / Desires / Values … power vs freedom, family vs mastery, etc.
MGTOW is alive and well. Now, men are literally going away.
Passport Bros!
Confirming that
Your eyes are open, and you can see.
What I can see is the ultimate stack/custom for me would be one that would let me answer, without hyperbole (beyond it not being literally my name lol) or hubris,
“I AM.”
I haven’t run the Emperor series, but Primal seems totally sigma to me.
This is actually quite profound. Have you read “Unveiled Mysteries” by Godfré Ray King.
Thanks. 
I have not, I’ve added it to my list to look up though!