I was told by a former Polar buddy of mine that Polar was kept separate because they held the China slot rights that could not be transferred to Atlas as well as the South American route authorities.
The pilot contracts were quite different, too, but I'm sure they are a lot closer now. So it looks like an already low cost carrier is going to be undercut by another low rent outfit from cockroach corner in Miami. Pretty sad for this industry. I'm glad to be out of freight right now. (although boxes don't b##ch.)