i think it’s ok to have narrative events, they just need to be good, and avoid railroading the player too much.
I have a concept where the antiquity military legacy is replaced entirely by a system of "feats" which generally correspond to tactical events that would most naturally happen if you're having big warfare and winning it. So, in antiquity, there would be less emphasis on conquering all of another player's cities and more on military prowess and maybe the exchange of a couple of settlements on average (without removing the conquest victory at the base).
One feat would be "win a decisive battle." So I have this vision of a simple algorithm that is troops concentration within a certain tile radius, and it triggers the decisive battle, and then once a certain number of troops leave the radius, are defeated, or a timer runs out, then the battle is over with a winner declare (earning the "feat") or the battle becomes "ultimately indecisive".
The point is that while you're naturally playing, "a decisive battle is occurring" would be a narrative event that circumscribes whether you get the feat or not.
Another feat could be having an epic siege of a citadel, etc.
With this in mind, you could have non-military events. I think the easiest way to integrate these would be to have complementary events. If I trigger an event from having lots of active trade routes, then my leader's event would increase the likelihood of other leader's complementary events being triggered (such as culture from trade). It should be made clear what the trigger and complementarity was in the dialogue.
These events should be about half as good as government/celebration bonuses, over one category rather than two. But, you could strategize how to stack them and get multiple triggered at once.
There should also be a menu panel that shows which events are nearing potential trigger, including a window of all inactive, possible events. I suppose events can have a success bonus, a prestige bonus, and a failure bonus depending on how you manage the event. Failure bonus means something that's not a total punishment (because you'd fail a path only after already taking a blow to your plans), but a weaker bonus in a different category than the event's (like a dark legacy path) tied to a slight nerf of the event's category.
The system feels analogous to the Civ VI civic boosts, except with potential for nice historical flavor which does, however, depend on good writing.