The lore that is described in the Enyclopedia is all very interesting and cool: Charas the original capital that was abandoned and fell, the betrayal in Lageta, the harsh climate of Danustica... As a passionate Souls player I've grown to like hunting bits of lore, however hidden they may be, in order to gain as much knowledge about the setting as possible.
The thing about Bannerlord lore is that it cannot escape the veeeery small confines of text boxes in an encyclopedia, and the lines of dialogue in the main quest. The city scenes aren't used for environmental storytelling and you aren't rewarded anyway for seeking stories inside of them.
Charas, despite being the cradle of the Calradian Empire, shows no sign of its original architecture, same goes for Paravenos and really any city that has changed hands in its history (I don't mind the former Palaic cities having their cultural heritage erased, that could become a well told story of cultural g*nocide) shows no sign of its supposed original occupants. Let alone the possibility for exploration, quest variety is also a problem: the triggers for "issues" to pop up pay no heed to culture or settlement, you are never going to get Vlandian only issues or Khuzait only issues to flesh out the cultures, let alone Charas exclusive issues or Marunath exclusive issues.
I'm going to direct very faint praise for Battanian towns, since they really look like remnants of a once prosperous civilization, approaching its doom within 170 years. Though no context is given to these ruins beyond the "decline" narrative.
As a huge history buff myself, I think we should thread with caution when discussing the lore of a game like Bannerlord. The year is 1080 AD and yet the Roman faction is still going (not well, mind you, but alive still), as well as a Celtic faction (though on its last legs as well). How would these armies look like if they lived long enough to witness the advent of heavy cavalry and the decline of heavy infantry? It's alright to use history to have some standards for what you can expect, but we shouldn't take it too far. The Calradian empire looks like a declining Rome but it's not yet fully "Byzantinized" to me.