Until freighter pay equals pax pay there will always be Commands out of seniority, whether it's DECs or S/Os, F/Os, it's a pay rise, a basing or not having to wait 10 years for a pax command.
Freighter pay will never equal pax pay as it will stall when it comes to bypass pay. The most junior pilot on the seniority list is often now a CAPTAIN!
The only way to fix it is a common jet pay, command will go back to strict seniority, however, as said bypass pay will be an issue, perhaps a forfeit of some bypass pay for short term pain vs long term gain?
I think you'd see guys who joined CX with the plan for a rapid command on the freighter rethinking their future in CX.