Division record only matters for ties within the division.
With 2-3 teams, after head to head, the next tiebreaker is conference record, then common opponents.
If the Bears win out, they would win any tiebreaker with Seattle or LA.
If the Bears lose to the Niners, they can't get the 1 seed.
If the Bears beat the Niners and lose to the Lions, they would need a Philly loss, a Niners loss, 2 Seattle losses and an LA loss to finish with the 1 seed.