Think about it: You're sitting around, minding your own business and all of a sudden an unidentified alien spacecraft comes shrieking down from the sky, and in less time than it takes you to make a sandwich, all resistance is utterly crushed and you're either dead or enslaved, never to see your friends or family ever again. In a competent film, this would be among the scariest of nightmare scenarios!
Jonnie and his Scots slaughter all the Brigantes by incinerating them in a platform in the book. It's mentioned the Brigantes brought with them their women and children. Which means that the entire tribe has become extinct.
Even worse, the Tolneps and Psychlos are also doomed to extinction, and the narrative goes in great lengths to confirm this.
The bronze and silver capsules implanted in the brains of all Psychlos are repeatedly said to have been implanted when they were pups (children) less than a few months old. Since only male Psychlos with the silver capsule are allowed to be taught mathematics and engineering concepts, this implies a pretty stark caste or class system. Literally consigned from birth to remain ignorant.
