How about this idea:
1) Lists are integrated by relative seniority (bear with me for a second)
2) In addition, you tally up what percentage you currently need to hold certain position at your current company based on your current position #. Say 15% for widebody Capt, 40 % for midbody Capt, etc.
So, if you need 15 % seniority to hold widebody capt at Delta(original company), When you finally reach 15% seniority based on this Delta seniority (not the merged seniority) you bid widebody Capt. Then, if you are not awarded widebody Capt at that time, the company will still be required to pay you at Widebody rates, unless you don't bid widebody capt.
This idea basically solves the pay issue if MGT will agree to it.
Granted, if you were supposed to be able to fly the 787 in 5 years as Capt, you might not actually get to do that, but at least you would be getting paid as if you did.
I would bet the amount of people actually affected would still be minimal, and would bridge the gap in time until you can actually hold widebody capt.
In addition, not everybody "wants" to fly widebodies. There are plenty of guys out there working for Delta and NWA who could fly mid or widebody capt, but prefer the type of flying in narrowbodies.
This puts the onus back on management and increases pay for everyone involved, since I would argue that is the biggest problem with mergers; people are afraid it will affect their wallets.
Any comments on this idea?