I've read over the last ten pages or so of this discussion. I'm somewhat amazed at a fair number of the posts.
I think newKnow has done an exceptional job of trying to explain what the arbitrators are likely to decide.
I have no dog in this fight and confess to being a DAL guy. My recollection is that DAL pay rates were somewhat higher than the pay rates of NWA. I don't think that counted for anything with our arbitrators. NWA had a pilot group that was somewhat older and had more people slated to retire sooner. That was factored in somewhat, but wasn't a huge issue.
I've flown with quite a number of pilots at Delta who were former Western or former Pan Am. The vast, vast majority were great to fly with. However there were exceptions and these were almost always pilots who were exceedingly bitter over how their SLI went.
Whatever the arbitrators decide, do your best to "move on". Don't be bitter and don't let that emotion ruin the cockpit atmosphere. Life is too short ....