Responses
I don’t think he’s lying.
1) They were dying in the apocalypse without Guwon, why would they just let Guwon die and go back to the apocalypse.
2) It could just be that he met Guwon in an earlier stage of development. We see how innocent or unaware Guwon is at seemingly normal things. He tells the MC to teach it to him. It could be that when the doc first met Guwon he hadn’t learnt the importance of children yet. But now he has a town and he wants to maintain the town and obviously then you’d need children otherwise what will happen to the population.
3) point is possible.
I still think the one controlled is Guwon and humans are just using him as a pawn because
1) if he makes everyone so miserable, they could let him die, everyone has a skill to survive in this town but they still chose to keep him alive.
2) I don't trust the doctor when he said he killed his kids, because then why other kids are in this town if they're not "useful" in Guwon's eyes. He even was searching for a teacher for them.
3) When he was saying "complicated" words he probably was repeating what humans been drilling in his brain to convince him to do all the dirty job.