Greetings from France !
I would love too to have Battle Sisters, but I understand the problem of having a huge load of rework with the game’s texts. So I thought of a few options to more or less ” turn around ” the obstacle :
1) The Silent Sisters : the idea is to add the basics : women can be recruited, equiped, trained, will fight and die, same as your brothers, BUT will NEVER interact in events, random or not. The negative side, is, of course, total lack of atmosphere / background / logic, with Battle Sisters never saying or reacting about anything.
2) The Hidden Heroine : an ingame feminine variant of the Lone Wolf ; once you’ve earned enough renown, you can hear rumors about a lone woman with great fighting skills ; so you’ll have to find her if you want her to join your compagny. Like the first option, she will never be involved in random events (so no texts change), BUT she can have her own sentences with her personal quest (slaying a world boss, recover an artifact, or whatever you like).
3) The NPC : a small new factions of Amazons / white witches / sisterhood of women who decided to take arms against threats like hags, necromancers or cultists, and to do it in their own way (after all, who can tell if witch hunters of Battle Brothers’ world never burned innocent people ?). You won’t be allowed to recruit them, but they will appear randomly in the map and you will be able to help / be saved by them by fighting side by side, in the same manner you can join your forces to a neutral / friendly group (such as peasants, caravan, miliatia or noble house men at arms) when facing a mutual enemy.