I think the positions merged in a SLI would be the stovepipe positions, not those actually holding them. So there would be X number of AA 777 captain, X number of US 330 captains, ect on down the list. Then then they go down the list and insert by seniority order.
Just because all AA guys have been offered recall doesn't mean there was room for all of them. If everyone had taken it in seniority order, then there may have been some that had not been offered recall yet.
Just saying, no idea of what the real AA numbers look like. I believe all west pilots have been offered recall, but several deferred, so there may be some over there below the "active line".