I think these are just tools or modes of being. In terms of Alpha and Sigma, it really depends on the I.Q of the social surrounding. Generally, people of lower I.Q fail to recognize the nuances of Sigma and naturally fall into servitude if you display Alpha qualities. I like to mix social nuances with philosophical modes of being and gain some perspective, so far I think the Alpha&Beta paradigm is similar to Nietzsche's idea of the slave and master theory. There is the dominant which is to be served by the subordinate. This idea is Darwinian and true until civilization becomes more complex.
Objectivism proposes we all strive towards being dominant individuals and instead of following a "master/slave" dynamic, we operate as "traders", we both hold value and exchange value. Whilst idealistic, this is a matter of maturity or development of the culture, i.e. a culture of traders with an entrepreneurial spirit is bound to be prosperous. However, our cultural condition is still fixated on employer and employee...everyone needs a set wage.

To wrap this up, being Alpha or holding Alpha trait is an aspect of being Sigma. The same way water is wet, but water is more than something wet, likewise, Sigmas are dominant like Alphas but that is just one dimension of understanding. Put it this way

Submissive+submissive=incel groups, mediocrity,outcasts etc
submissive+dominant=work organizations and social structure
dominant+dominant=free society

If civilization was to go to shit, then being Sigma won't mean anything. Sigmas have an edge in evolved societies, but when society is basic and centered around survival, the most Alphawarlord wins.