It is a nice blog and yeah the options and possibilities are known in other games "looking at you crusader kings2".
So we can execute the lords, heretics, maybe mercenaries or other companions.
I would like to see multiple options there like
a. releasing a lord can positively and negatively affect you depend on the relation between you and the said lord or what happend. If you killed their loved or liked personels or family members they could swear revenge on you if you release them or just try to backstab you.
b. an option to avoid or finish battles with duel invitations so the leaders of the armies could engage in a duel and the one who left stand won and the opponents army retreat / tries to catch you.
c. If you in battle hurt your opponent but you decided you will be merciful then would be nice some option to release the said lords or just first aid him/her then you can have some chance "again on opinion and relation" make the lord serve you or make closer relationship with him/her.
d. keep the lord as a slave and when you meet with his/her faction you could barter and demand for land / family member / money or goods depend on the rank of your captured lord.
e. random even before the execution or during your trip.
- the lord dies accidentaly (still causes relation degradation-improvement on others)
- your captured lord / prisoner escape
- joining your forces
- joining to your forces but with compromises / claims
- trying to kill you during the night - other companies tries to capture / recapture your prisoner
- starving or get ill during the trip / if you haven't medicines or enough ration.
f. make moral decisions in your peoples head / some could turn against you / agreeing with your decision. So if you kill a honorable or atleast a kind person or a wealthy one then your army could consider you are a bad leader and tries to kill you or just leave you alone in the next major battle so your chances to win a battle drop because of this.
Beyond this I have plentiful ideas but I think I will leave the ideas for others too.
Basically a crusader king like diplomacy and moral system with some add ons.