I'm still trying to wrap my head around the idea that Khan could ever have considered McGivers his "beloved wife" when we saw how he basically beat the crap out of her when they met in "Space Seed".
Abusers often make claims like this. That doesn't mean they actually love their victims, of course, but they often claim they do, and they may even think they do. (Because for them, "love" is about control.)
Khan is too strong to irrationally beat his wife without killing her.
Abuse isn't always about losing control of anger. Abusers can use violence quite intentionally and in a calculated manner.
He acts like a small-time cult leader, in it for th p##sy, when actually Khan was the king of a huge kingdom.
I mean, "acts like a cult leader and is obsessed with sexually dominating multiple women" is a pretty common description of male dictators. Idi Amin, Muammar Gaddafi, Kim Jung-il, Henry VIII of England, Charles II of England, Benito Mussolini, etc. It's not uncommon amongst leaders of nominally democratic states, either; just ask Donald Trump, Silvio Berlusconni, or Bill Clinton.
It's possible that the civil service that grew up around him, facilitated the growth and continuity of rule.
Khan was just along for the ride, and anyone sitting on his throne would do, to keep the empire errect.
For whatever it's worth, the two-part
Eugenics Wars novel series by Greg Cox depicts Khan as coming to power unofficially, as a sort of "power behind the throne," with overt formal governance still being nominally maintained by (IIRC) the government of the Republic of India and the governments of other nearby states he'd assumed power over.
I'm not convinced Augments are even capable of love.
Augments are like Nietscheans from Andromeda. Cold, calculating, ruthless, caring only for power. Love would be an alien concept to them.
I mean, Julian Bashir is an Augment, and he's certainly capable of love. So is Sarina Douglas. Jack, Patrick, and Lauren all seemed capable of love to me, even if they were mentally disordered.
There is a
possibility that the specific group of Augments created by the folks who created Khan might not be capable of love as a result of the genetic alterations made to them by their creators. But, even then, I think that would be a very broad conclusion to drawn on the basis of an exceedingly small sample size -- we've basically only met Khan, his followers, and a handful of Augments from ENT Season Four. And frankly it's unclear what kinds of childhoods any of them had; we know the ENT Augments were raised by Arik Soong, who was probably emotionally abusive and raised them with fantasies of superiority and dominance.
And frankly, I don't really see why Khan wouldn't have been deposed by his Augment followers at some point in the course of his reign if they didn't love him in some manner. He fucked up enough that a group of Augments who didn't experience a feeling of sentimental loyalty to him should have tried to overthrow him at some point.
I think it makes much more sense to assume that
Khan is incapable of love, and that specific individuals from the group of Augments he was created from may not be capable of love, than to assume that
all Augments are incapable of love.