The short answer is that a list that accounts for each pilot's current bid position doesn't help much if we are operating two separate operations, and is absolutely useless in an SLI. Seniority number is everything, bid position is subject to all kinds of things that don't matter in an SLI.
APA has said only one consistent thing with regard to the east/west list: that they don't want to inherit the fight. They want one US list--it doesn't have to make everyone happy, but it would be nice if it had legal justification, so that part of the new AA list is not subject to continuing legal challenge.
What USAPA wants to put forth as that list makes no difference, as it is negotiating only for east interests. The path that leads us to a single list to give to APA will come through the courts, will likely be appealed, and will eventually be the final answer. And in all likelihood, it will be Nicolau's list.
USAPA knows this, but their strategy was/is/always will be this: upgrade as many F/Os as possible before the Nic is imposed, delaying that date through litigation as long as possible, banking on the reasonable assumption that no bump/no flush will be in effect after the final SLI. Largely, this strategy is working like a champ, and I don't see how it stops working in the near term. Will west pilots ever be compensated for these lost earnings? Great question.