I'm not sure if anyone is interested in seeing this, but I ran overall system seniority for a guy hired at Delta today vs a guy hired at Southwest 10 months ago. Both with approximately 33 years left of flying. I then compared that system seniority to what it took to hold each aircraft and seat in ATL compared to what it took to hold each seat in one of our junior bases (HOU) and senior bases (MCO) at Southwest.

I was surprised to see that narrowbody progression at Delta in ATL closely mirrors our career progression at one of our junior bases here at Southwest. It also appears that widebody flying will make up a small part of your career at Delta if you are unwilling to sit at the bottom of the list. Keep in mind this is only in ATL though. NYC would be totally different. And also keep in mind this assumes 1% growth per year at Southwest and obviously doesn't take into account another merger/acquisition. I also realize the Delta calculator doesn't take into account front end hiring and is based off hiring for retirements alone.

Hope this helps anyone else trying to figure out what to do!