But if its relative seniority, you won't lose bidding power and there will be more opportunities going forward....

Isn't that what DAL argued in the NWA/DAL SLI?

I'm a way low man on the totem pole so anyone coming in ahead of me will have a potential impact on my future, but I do agree that a relative percentage SLI with adjustments for fleet makeup/percentage wide to narrow would absolutely be fair.