I posted a follow up to my prior article. Be gentle.
http://ragingowlbear.blogspot.com/2014/06/d-combat-math-internet-stikes-back.html
Looking at your math, it looks like you didn't take the AD&D Fighter's multiple attacks per round into account at the higher levels. Don't forget the Fighter gets 3 attacks / 2 rounds at 7th level rising to 2 attacks per round at 13th (see chart on page 25 PHB). That will nudge the 10th level Fighter's expected damage up 50%.