I have an Idea about making the Brothers stronger .
Make them able to train with each other! This could be done by 3 different ways.
1) An Event where 2 of your brothers start training with each other (just like the event with the bows)
2) An option During camp That have limits like : If a brother do train, he can do it again after 4-5 Days.
3) Training centers In towns(only large towns) where will have some requirements for a brother to get inside like… lets see
train in Melee skill Requires : lvl 4 brother with 60 melee skill, A brother with a melee skill of 100 cannot enter.
what bonuses will they have? well.. idk… mayby some xp but only afew (like 10~20) or… maybe… +1 in one random stat…