The only thing I can tell with certainty is that the difference between offensive and defensive ratings has quite obvious diminishing returns. It's quite evident by the repetitive posts in the "Oh my god how did I lose" thread, where people complain they lost even though their offense was a hair better than the opponent's offense (and both had no defense to speak of).
"I don't know half of you half as well as I should like; and I like less than half of you half as well as you deserve."