Idk which order common games/conference record goes here at MFN but for the NFL common games is first to determine which South team is in 2nd place if both finish 9-7. Birmingham wins that tiebreaker but would lose conference record if they lose and the Steamer win.
We'll assume the NFL version is correct and seems to be confirmed by MFN's placement of an X next to Birmingham. "Seems to be".
So if we take that as fact, the #7 seed could come down to a tiebreaker between Shreveport and Charlotte. They didn't play and for wildcard ties not involving teams from the same division, conference record is the next tiebreaker. Charlotte wins that one.