Wait.did you marry your sister to a other clan?
Heroes who leave the player clan lose their protection against battle death, only members of the player clan have protection against battle deaths.
And do not marry female clan members to other clans, it is not worth it, you gain nothing and only get a potential new enemy.
And the amount of battle deaths is way to low, because the procreation is to high, after 20 years all Castles/Towns have more than 20 pages and way to many living heroes.
They should raise it back to 10% for mission battles and keep the 2% for simulated battles.
The clan was on the verge of dying out (1 guy left) and they were part of my Kingdom. It seemed pragmatic to keep them around. Granted I've learned you're probably better off raising Companions to peerage then trying to convert Clans. Also once you reach a certain size no one seems willing to join anymore anyways.
I absolutely will not play this game with such a high battle death rate, completely breaks the game. The biggest reason I stopped playing in 2021. I do not enjoy re-loading battles I won, just cause an Army/Clan member died, or effectively wiping out all neighboring Kingdoms.
If you want to kill everyone so there's no one to fight you, you've got Execute as an option (admittedly it's poorly implemented at this time.)
Nah, try playing the late game and you'll understand that all lords are almost invincible and death rate is close to 0 at this point.
I remember, when a feature was only implemented, and you travelled along with an army, you leader could be suddenly killed in battle, your army disassembled and you with a bunch of other lords ended up surrounded by enemy forces, had to flee somehow. Now such outcome is impossible, because it feels like death in battle is almost as disabled. Of 7 companions I had only ONE died in battle in 27 YEARS (yeah, some may see it as a pro rather than a con, but for such people there's an option to disable death at all!)!
So, no, I can't agree with any statement the death rate is "good". With that "good" rate the function is dead, useless and meaningless.
Not sure what qualifies as "late game", my PC is like 60 years old and technically I won around year 1124.
All I know is death rate was ridiculous early last year, you could easily get all your companions killed, and certainly wipe out all Culture specific Companions quite easily unless you reloaded regularly. If this was a different game that sort of death rate might work, but given how easy it is to get KO'd, and that the Nobles/Companions charge into battle with little caution. Yeah not good. You can't even create custom formations anymore.
Here's a list of the battle dead from my latest character, not sure how many died from player battles (I'd say a dozen or so), ugh can't believe I'm doing this:
Aserai: 12 Clans, 13 Battle Deaths
Battania: 1 Clan, 2 Battle Deaths
Empire: 41 Clans, 52 Battle Deaths
Sturgia: 16 Clans, 9 Battle Deaths
Vlandia: 15 Clans, 18 Battle Deaths
Khuzait: 7 Clans, 7 Battle Deaths
8 Dead Clans, 15 Battle Deaths
So 116 Battle Deaths, seems reasonable to me when you start factoring in old age and childbirth deaths.
Admittedly Sturgia and Vlandia look to be having a sizeable baby-boom, with some 20+ member clans. Sturgia absorbed like 5 Rebel Clans, which I'd say is probably too many and most responsible for some of that. But achieving a perfect balance is impossible unless you hard-code in "plague deaths" as another means of population control.
Simulated battle deaths could probably be raised like 1%, but I would not go beyond that.
Maybe TW can implement a hazard mode with like 10% battle death 5% simulated death, then you can rejoice in random cultural genocide. Considering that you can't change the culture of settlements you'd be creating lots of problems for yourself, unless you're hoping for a ton of Rebel clans to rise up.
I'm sure someone will make a mod to adjust battle deaths, etc. - but as the vanilla game goes I think it should stay as is.