Just create a single bloody list based on DOJ and tag each crew as CX or KA, you want transparency then DOJ it is, it's the backbone of a seniority system, then let the union's not the company come to a solution that's agreeable for the future, negotiating with the company only ends up in a reduction of terms. Perhaps then stuff like vacancy bidding can come to fruition without the seniority list screwing it up and again leading to negotiation with the company. Wrestling with a pig comes to mind.
DOJ would seem simple but the DFO wants to blend the two lists one for one. That is to say, number one in CX followed by number one in KA and so on. First used when BEA bought out Eastern in the UK in the 1960's this has been the default seniority merging method used repeatedly. In the USA this would be laughed at but we are not in the UK. How the canadian and US based pilots would fit in is the problem. The immediate advantage to any KA driver is that with only 1000 pilots and CX 3500 a KA pilot will always find him/herself in the top 2000 of a 4500 strong list. Win Win for KA.