Can someone explain how a bit more how the boarding process on AA works?
1) I paid for MCE on the first leg and was Group 5, however I was instructed to board behind Group 8 due to my "row number." Boarding involved two lanes and there was no signage except for a sign that said "American Airlines Boarding" in between the two (no group numbers like at the gate of my second segment). Upon trying to board with people holding Group 8 tickets, I was placed into the back of a separate third line that formed behind more Group 8 ticket holders (while others were allowed to board) and told to wait 5 minutes by the agent - all while people continued to board via both lanes with all group numbers. There were no announcements of any kind until after I got to the podium and then the agent made an announcement saying "Rows 16 and above only" on the loudspeaker, like I did something wrong. Any ideas what was going on here?
2) On my second segment, I was Group 8 (not MCE seat on this segment). I moved three seats back and got Group 6 all of a sudden. An announcement was also made at the gate telling passengers without a group to board as Group 7, ahead of my original ticket. What exactly is the difference between Groups 6, 7, and 8? I know group 9 is basic economy, but what are the other main boarding groups other than 5? I really don't get it.