If events are implemented in the game in a historical manner I would hope they are an option that can be turned on or off as desired. Personally I dislike the idea of being forced into historically accurate events when we are not playing a historically accurate game.
Yes, Sun Ce was assassinated in real life... but actually forcing this event to occur each game (or making it very likely that Sun Ce will have it occur) is rather boring and unrealistic (to the game's story & circumstances, of course). In a game where we are creating a historically different outcome, why would an event tied to the situation that occured in reality, and likely didn't occur in the game, come to pass?
Such events would force the game down a specific path, when the whole point is to recreate history. If Sun Ce is set to die at the same time (or near enough) each game, then why not prevent any of the minor factions from capturing cities from Warlords like Cao Cao? That's what happened after all.
Instead I would propose that you have random events based on what is going on in the world. Certain heroes have certain traits, this could be used in conjunction with other factors to generate some cool events that could logically take place.
If Faction A is at war with Faction B for a period of time, there is an increasing chance that a hero from Faction A (or a close ally of Faction A) will attempt an assassination of a hero (or the Leader??) of Faction B.
You could have modifers such as, the longer the war lasts the more chance of occuring.
The more involved heroes are the more chance they will attempt the assassination (or be assassinated, if they are successfully killing enemy units!).
Certain heroes that, in real life, were known for attempting assassinations (or successfully achieving them) will have a greater chance of making the attempt.
You could then have other events, such as Heroes betraying their nation if the war is going badly and killing (or attempting to kill) a former ally in the process of switching sides. Heroes renowned for this may be more likely to do so (and be more successful at killing someone in the process - example being Lu Bu).
So if a war is going badly they are more likely to betray (the worse the kill ratio between Faction A & Faction B toward eachother - including captured cities, hero kills etc).
Or if their current Faction is a sinking ship (the more cities lost in x turns the greater the chance) they might jump ship.
So rather than being set events that only occur between set characters, or set factions, at set times etc, make them random but related to what is currently occuring. It would give some real depth to the story that is unfolding in your game.
Just a few thoughts.
