In the past four years, about 1,000 AA pilots retired early so they could get their lump sum option for their A plan and so they could use the 60 day look-back valuation for their B plan. That has left AA with very few 60-65 year olds and has "youthenized" the APA list (to use a "Michael Scottism"). In fact, AA might be light on 55-60 year olds as well. Since no such inducement for early retirement has existed for US East pilots over the past few years, I have to assume that the average age at US East is substantially higher than the average age at AA. And I'd be willing to bet some serious money that the APA pilots at AA would not willingly entertain a DOH integration.
As I've posted before, the arbitration would probably consider the Nic list as the official list of US Airways and would combine that list with the AA list in some fair and equitable fashion that would no doubt enrage the US East pilots, might annoy the US West pilots and wouldn't make the AA APA natives all that happy. In other words, a fair integration.