I don't think one can make one attrocity more "relevant" than others. Atrocities are atrocities no matter race or gender. The reasons behind the atrocities can have a wide range of causes centered around those folks who commit them. I think your generalization about only gentlemen were the upper class and the lower were the roughs stretches it quite a bit...war can bring out the worst in anyone, rich or poor. People who commit atrocities, especially during the civil war, had issues and civil strife brings out the worst on a more regular basis. I think you can look into why these particular men were so ruthless and cmopare it to their backgrounds etc. I know there is an account of their arrest etc in one of the papers.