No, that's exactly what I'm saying I think you're just reading it differently. There is no perfect answer. I think there would have to be some stipulations associated with the movement from one company to the next. Here are a couple of thoughts:
1) Seat locked for 1 to 2 years
2) Seniority is for pay purposes / benefits
3) No direct Captain entry
4) 10% to 20% reduction of seniority number (if you are a ten year pilot and move you lose 1 to 2 years of seniority), makes moving more deliberate.

I do understand your argument, but I can tell you as a FO who has only been at this for a couple of years and would be at the bottom of the "national" list, I wouldn't have any problem with one of my peers getting paid what they deserve.