Was Lon Chaney's character supposed to be a Turkish Janissary?
His character's surname, Kebussyan, sounds almost Armenian. And I'm assuming the slurry nickname was supposed to indicate that he was Muslim by religion.
Now, from what I've been able to dig up, the real-life Janissaries always "recruited" non-Turkish boys for training. That this elite corps of soldiers, first organized in the 14th century, was finally abolished by the Turkish government circa 1823. That the French army founded the Foreign Legion roughly ten years later. And that the U.S. Cavalry briefly experimented with camels, for southwestern desert duty, during the 1850's.
So, I'm wildly guessing, here, that Trooper Kebussyan might've been an Islamicized Armenian soldier of fortune who came to the States via the Foreign Legion and Uncle Sam's Camel Corps.