That's funny. Thought Cohan, Cohen, whatever, was a Jewish name. It is the name for the priests... Maybe they're just similar sounding names.
Have you ever seen a John Wayne movie called "The Quiet Man"? It is set in Ireland. In one scene, John Wayne and another character pull up in front of a pub named "Cohan's." John Wayne looks at the sign, and his companion says, "Over here, we pronounce it Co-HAN."
Think of George M. Cohan and his family, "The Four Cohans". As Irish as they came. :)