Complex sentence: He has neither Saul Panzer's genius for tailing, nor Fred Durkin's bulldog tenacity, but he'is' handsome, and Stout furnishes him more complex motives than he does Saul or Fred.
Split into simpler sentences: He has neither Saul Panzer's genius for tailing, nor Fred Durkin's bulldog tenacity. But he "is" handsome, and Stout furnishes him more complex motives than he does Saul or Fred.