The issue has come up since we do not have mergers between equals in some cases. One carrier is stronger than the other. Progression to the LHS has been quicker for the pilots at the stronger carrier. The pilots at the struggling carrier have faced stagnation or furloughs. They cannot expect to jump to the LHS from furlough or reserve F/O just because they have sat stagnant for 20 years in the RHS. The job they brought to the merger is the seat and the jet they are in, no more.
CAL/UAL is a prime example of this. CAL captains had as little as 5 years on property. UAL had furloughed back to 1999 hires. How do you integrate that? Rationed spots on the list based on aircraft type. UAL has more wide bodies, they get the bulk of those positions. CAL has more narrowbodies, the ratio is more in their favor. Furloughees get put on the bottom below the last active pilot.
In our case at America West/ Us Air the top 517 slots went to Us Air pilots since they had 20 wide bodies. The rest was done on a roughly 3 for 2 ratio after the first 517, 3 East pilots for every 2 West pilots. That was the Nicolau Award that the UsAir East pilots left ALPA over. 7 years later we have no joint contract and they make $25 per hour less than the West pilots, and we wait for a judge to rule whether the company is bound to use the list that they accepted 4 years ago but never implemented in a contract.