It's interesting, you won a reader
A king is just another word that means leader.
A leader who denigrates half of his people just out of lust is just an immature being who will be trampled on by a future revolution.
A true leader is someone who fights alongside all people. All the men, all the women, all the children, all the elderly, all of them.
A true kingdom building isn't about popular with some people, it is about the future.
I Tried to read 'The Legendary Mechanic' once , but it was a little boring. Maybe I will give it another chance...
Isn't 'Advent of the Archmage' a harem?
In 'Overlord' the protagonist already starts as a ruler, complete with a castle and subjects. It isn't what I am looking for.