AOE3’s campaign narrative is fictional character-centric. That’s an impression very embedded and hard to alter. However it is still possible to achieve good historicity like the AOE1/2 ones even with the formula and I think TWC campaigns are good examples to follow.
The vanilla campaign had a strong resemblance with AOM ones: the “team of heroes” travel from place to place, run into all events, help someone out, then hop into another place. That’s great for AOM but not for AOE where people have certain expectations. It skimmed through multiple real historical events like Seven Years War or Bolivar’s Revolutions but the representations were shallow.
TWC followed the fictional character narrative. The heroes still had their own storyline, but they were deeply involved in consecutive series of events in a real coherent historical “campaign” (eg American Revolution). Most of the events were either real or had a real basis and again they were coherent. It’s fine to insert one or two semi-fictional or generic scenarios into the story as AOE2 also had that.
I wanted to use TAD as a good example too but it didn’t feel right to me. The Japanese and Indian campaigns had a strong and interesting historical basis, but most of the scenarios were fictional. You can hardly relate them with anything that really happened (Sekigahara is a great one though). And the Chinese one is just ****.
So I think the best formula for an AOE3 campaign is;
The fictional hero is a witness of the series of events, or a helper of a real important figure. The scenarios are mostly coherent, consecutive real events from the heroe’s perspective, and loosely follow the course of history. Just like the American Revolution campaign.
Also Sekighara is a great one: it was from the perspective of Kichiro (a fictional character), but had a good representation of the battle, like the placing of armies and even some real turning points (the death of Otani and the betrayal of Kobayshi). Fushimi is also okay. Shame that most other parts of the campaign are purely fictional ans generic.
For example,
The hero of a Napoleonic campaign could be a fictional bodyguard that followed him from the revolutions to Waterloo.
The hero of a Peter the Great campaign could be a Scottish advisor in his court.
Etc.
There are previous examples: the entire Saladin campaign in AOE2 was told from the perspective of a fictional Frankish prisoner turned into Saladin’s follower. And no one considera that campaign as not historical enough. It’s just that AOE3 campaigns have more character involvement.