Originally Posted by sailingfun

You do not understand how seniority lists are governed and controlled. Unions do not own or control the seniority lists. Management controls the seniority list and decides who to hire and fire. A union legally can exert limited control over the seniority list via the scope section with a requirement to merge seniority lists if their parent airline purchases another airline and they have negotiated such a provision in the contract.
Unions can’t however simply decide they are going to merge lists with another airline. The RLA requires transportation unions to be separate entities that can’t collude with each other. That is the reason ALPA is a association not a union. They provide support and services but each airline is a individual union even if under the ALPA umbrella.