I have to agree with
@Apocal, this is just the exact same issue as before. The original way of having boys be their fathers culture and girls their mothers culture was optimal. It allowed the opportunity to have some of your children be the correct governor type if you own lands outside of your culture and gave a reason to marry outside of your culture.
No, it is not quite the same issue as before, since children taking culture from their fathers greatly reduces the amount of clan members whose culture does not match the fixed culture of their clan. Because in the current situtation, where kids are born almost always into their father's clan but take their culture from their (foreign) mothers, cross-culture marriages lead to mismatches between the culture of the children and the clan. This is/can be an issue, because it means that fiefs held by the clan which match the culture of the clan could then face a wrong governor culture loyalty penalty (once these children come of age and are appointed as governors).
I do agree however, that the downside of children taking culture from their fathers is that it does take away the ability for the player to influence the culture of their clan's children (exception: children of a female player character)
I think that each of the mentioned culture inheritance systems has its own advantages and disadvantages:
1. Children take culture from their mothers:
- Cross-culture marriages lead to culture mismatch between clan and clan members born from these marriages (unless the woman is clan leader, as children will then be part of her clan while also inheriting their culture from her).
- But the player can easily influence the culture of children born into the player's clan (exception: the children of a female player character, which will always have PC's culture).
- With this system there will be several AI clans who have governors with wrong culture in fiefs matching the clan's culture as the game goes on, simply because there will be quite many clan members whose culture does not match their clan's culture.
2. Children take culture from their fathers:
- Cross-culture marriages don't lead to culture mismatch between clan and clan members born from these marriages (unless the woman is clan leader).
- But the player cannot influence the culture of children born into the player's clan (exception: children of female PC).
- AI clans with wrong governor culture in fiefs matching the clan's culture will be rare, as only clans with female clan leaders would have children born with a culture different from the clan.
3. Sons take culture from their fathers, daughters from their mothers:
- Cross-culture marriage leads to some culture mismatch between clan and clan members.
- Most clan member's culture would probably match the clan's culture, as most children will be born into their father's clan and most sons will remain in that clan while most daughters will leave that clan once they marry.
- The player can easily influence the culture of daughters born into the player's clan, but not of sons (again exception children of female PC, where the reverse is true).
Also with the 1. system chances are high that there will be clans where all the clan members have a different culture than the clan itself as the game goes on, while these chances are low in the 2. system, and moderate in the 3. These clans will then always have a culture penalty (owner or governor) in any fief that they own.
Personally, my preferred solution would be that children always inherit the culture from their clan, but to also give the player the opportunity to educate the children of the player's clan in another culture, thereby changing their culture (maybe with the requirement that children can only be educated in a culture of their parents).