KO's post is halfway down this thread:
http://www.shrapnelcommunity.com/thr...672#Post541672
He seems to be saying that if there is enemy Luck or Misfortune in your province, then both have the same effect on the chance of a random event (increasing the chance), and whether it is a bad event (both enemy Luck and enemy Misfortune increase the chance of bad events). But he also says though that the event scale requirement does not go away -- if you've got enemy Luck3 in your province, that's better than Misfortune3, since you can't get any bad events that require less than Luck3 to occur.
I think it's entirely possible I've failed to understand him properly though. So please read the thread for yourselves.
Just from experience, I always seem to get way more horrible events in my provinces under enemy dominion from enemy misfortune scales than from enemy luck scales.