I don't believe a master list would offer portability of the job. Why would a airline management team ever hire a pilot they had to bring in at a higher pay rate and above the seniority of their existing pilots. It would upset the pilots on their list and cost more money. They would only hire pilots coming in at the bottom. Sometimes we forget that it is a management function to hire pilots. If they wanted loyality from their current pilots they would never hire some one in on top of them.