On the other hand, worm farms may help further the idea of "disgusting inhuman savages you don't feel bad about exterminating".
Trade though, is great. If you can interact with them in ways other than a javelin to the face, they become more than a threat to be eradicated and dismissed. Doubly so if they have unique ressources you can't get otherwise. Having different tribes with distinct behaviours/personalities as well. Simply having two camps of masklings wear different colors of clothing should be enough for the player to infer deeper differences and thus a more complex society, I think.