Using the unfortunate human tendency to project --- that is, to take one's failures, weaknesses, flaws and even "sameness", a charlatan uses these, as a poster boy (exemplar) to blame OTHERS for those failures and weaknesses. That's where the sameness comes in.
It's easy to take a more or less homogeneous group and blame a minority -- POC, Jews, immigrants, gays ... the list goes on, and it repeats through history. It's what Hitler did to the truly beaten down German people to convince them that first communists, then Jews then gays were "poisoning" the "master race".
In order to gain these "benefits", the leader forms a cult which reinforces people in a group-think way, using a giant propaganda machine, and threats of violence. A little violence goes a long way.
A "good" cult also "legitimizes" some normally forbidden behavior that many people harbor, and had to suppress in civil society, such as racism, antisemitism, abuse of minorities, equality for women, and sexual freedom (which actually reflects their own self-fears of inadequacy), or violence, anarchy, a kind of three-year-old saying NO to grown-up behavior.
In short, a cult unifies people by projecting failures and banality onto others, making them into "virtues" and also (which I think he left out as I nodded off) permission to do otherwise unacceptable things under the group banner of "we're not them".
The downside is that people give up their dignity, money, jobs, prospects and futures, all for "the one". and cult membership is always self-destructive just to obtain that group feeling, perverse privileges, and ability to blame others for one's failure or weakness.