The collective's image of mudmen is created by the potters to both sanitise and barbarise.
"Aren't they silly!"
"Look how primitive they are, wearing sticks and mud!"
Truly, every day we take their soil is another step closer to civilisation. They even come to the city sometimes to offer tribute of clay, to ceremoniously kowtow and offer the rites of their lands. But they're just actors, wandering troubadours covered in cheap imitation mud then sent on their way with a mouth full of silver. Just gypsum and ashes, not the good stuff, too valuable to waste on a ruse. We need neat and tidy masks fast, strong enough to last a day of parades and bowing. Make them look primitive, make them look safe.
The real mudmen are out there. The last survivors of their apocalypse, fighting back the ghosts from their shore.