In answer to your question, it depends on how the name is pronounced and how the person writing the name down heard it said. I have seen my ancestors' name spelled, Phelan, Phalen,Palin, Phalon, Phalin,Felin, etc........ Doesn't really matter how it is spelled.
My German Roederer's had their name spelled Roederer, Reederer, Roderer, Roder, Raderer. It's all the same family from a small area in the Black Forest.
Mary Kathryn/Katherine/Catherine Victor/Vicktor/Perrin