Really comes down to where people live... seniority has it purpose at AMF, but people are generally hired for a specific run/base. Seniority then plays a part IF the pilot wishes to move....you bid an open spot, then it goes public IF left open.
Most AMF positions are not really commutable (unless you have a a second place to live and don't mind only getting "home" for 24 hrs a week)....so most every AMF base seniority is more about do people like where they live...two of the Burbank runs have the most senior people in the company, but untill recently two were usually open, being covered by TDY or HBC filling in.
Cargo jobs are more of a lifestyle. Some people like it and stay for decades, some hate it.
Keep an eye on the job openings, AMF hires people for specific bases, and for many it's a dream come true. Have known many people over the years that live at the outstation (outstation based) that are home from maybe 10 am till 6 pm, and weekends from Saturday morning till Monday night. They get 6-8 hours sleep at night, and most take a short nap at home during the day. . Outstation runs are getting less common, since hiring a pilot to live in a smallish town can be hard.
Hub based runs are the opposite, but only home at night for a few hours.....
Guess some people will take any job...then watch for the run they want to open (some limits thought, usually a 6 month lock on a new base if I remember right).