Jerry I don't like the concept of pay banding but 1800 jobs? Lets be honest here. You posted the amount of training you expect from 800 retirements a year and translate that to job loss. What you don't factor in is how many training events there would be with pay banding. Pilots will still move for many reasons. Trips on equipment, pay raise to a new band, bored ect... I suspect that in the end the difference in training via pay banding into 4 groups verses what we have today might be a 10 percent reduction in training events. That would not translate to much of a job loss in most years even the peak.
I don't want pay banding because I think when you divorce yourself entirely from the revenue generation capabilities of the airframes you make it harder to generate future raises. Yes pay banding will cost jobs but nothing like 1800.
Pay banding was floated by Leo Mullins around 2000 and it went over like a lead ballon. Taxi speeds dropped to a crawl for a few days and management quickly retracted it. The rates they offered were good so it was the concept not the rates that were rejected. I don't see the pilot group going for it today.