White Scars
The White Scars are a chapter of SPESS MEHREENS. Who were lead by their Primarch Jaghatai Khan, who is IRL the son of Genghis Khan.
The White Scars are basically Mongols/Kazakhs, with bikes, who are space marines. SPACE MARINE MONGOL BIKERS, means you fucked up China.
Combining their nomadic pattern of conduct in both homeworld and Chapter, with their belief in a theistic religion, they might as well be Islamic Kazakhs.