[The Squatter of Amon Rûdh]

We know the name of at least one Easterling apart from Khamûl the Nazgûl: Brodda, who marries Húrin's kinswoman Aerin, and whom Túrin kills on his return to Hithlum.

My admittedly cursory examination of the appendices to The Lord of the Rings and The History of Middle-Earth have turned up no names for any Wainriders.