Not all Men of Rhudaur were Men of evil. Some were heroes or Men of noble deeds in their time. They are lost now, within the mire of this land and lost to the corruption of their people. Still, they exist in unmarked graves in these barrows.
Though the Rhudaur fell quickly, they had heroes, and not all the Rhudaur were part of the malignancy that crept into the land. There are five such heroes entombed within the Garth Agarwen barrows. You should visit their graves. If for no other reason than to know that these Men were not the culprits behind the great tragedy of this land.