I'm not a pilot, don't even play one on TV. I once posed this question in the regular pilots' thread; it got lost in the noise.
I can see how seniority is big thing for pilots. Not only does it determine routes and bids, it determines pay, since pay is based on a/c type. Rampers, gate agents, or f/as get the same pay regardless of a/c type worked. How about pilots at US be paid by seniority, regardless of a/c type? Several European carriers do this. Some years ago, I chatted with a grey haired SK captain. Tired of crossing 12 time zones in one day and being away for days at a time, he had switched from the 767 to the MD-80. No more CPH-BKK-SIN runs for him, a double turn on the CPH-ARN shuttle and back to his own backyard and bed every night. This also enables less senior flight crew to fly the bigs birds earlier than otherwise.
Just asking. Flame away.