"You also need to list the average for 3rd Place +1pt as that's what you need for 2nd place, so will probably be a couple of points less than the 87 average that 2nd place ends up with".
A very good point and a very interesting result.
The average for 3rd place is 81 points (median is 80).
Based on this average plus 1 point, a further 22 (7 wins 1 draw and 6 defeats) from the last 14 games would normally bring automatic promotion.
But as soeone once said: "It's a funny old game, Saints!"