Hmm... according to the Monsters page in the wiki it appears that the 'actual defence' stat is 90% of defence stat plus 90% of ML variance. Is the KoLmafia defence stat already running at 90%, or does that need to be lowered in the consideration as well?
New patch here... includes both base defence and ML defence in the 90% calculation, as this appears from any spading I've been able to find to be the proper calculation.