When Dad started writing what he called "The Blue Horse Story" he didn't know what it was going to turn into. He tried to nudge it in several different directions, one of them was as a Sackett, before it took off. He probably chose to not make it a Sackett because he didn't want to write a Sackett story that did nothing to further the series. With "Higgens" he was just having fun. There will be a Passin Through Lost Treasures Postscript edition our soon that will tell the whole story.