Well, I guess it's a case of should random events be for flavor, or should they have serious impact? I would imagine something like a major invasion would be handled via the quest system, so you would still have to act.
The reason I would prefer not to have devastating random events is I would hate to be set back hugely or crippled by events out of my control. What if you had a random event hand you a plague that the random number generator determined killed half your units? Then you had to deal with either other players or try to complete quests with that handicap.
I'd rather be in that situation due to my losing a battle or making a dumb decision versus a chance event.