If empire 2 is ever made, it will have a grand total of three factions, each with three hero characters. Every additional faction will be DLC.
Friedrich of Prussia: Hero with exceptionally high armor vs enemy gunpowder (based on the anecdote how his cigarette wallet saved him from a bullet once), can recruit a special unit of 2 meter tall giant grenadiers
Empress Maria Theresia: Girlboss hero with a varied unit roster because the Austrian Empire has so many ethnicities in it, but having too many different units in your army can lead to a Karansebes event
King George: Gets a massive bonus on taxes but it increases revolt risk, gets unique spell "Britannia rules the waves" that makes ships invincible for 5 seconds