1- All classes should be able to use war horses without needing to evolve some specific skill of cavalry. The difference is that knights used their horses more skillfully, and non-knights were only able to use the war horses for transportation. Or, normal horses would have more stamina just for transportation.
2- Archers could have daggers beyond the bows. Thus there was no need to evolve footman or militia skills to use melee weapon.
3 - The armors are mostly with armor design from the east or in the case of assalteur class, the royal armor has a design that corresponds to a type of armor much used in the Middle Ages only for military stops or tournaments. I think it would be very good to add larger varieties of armor or parts of them, such as mesh heights, metal plate dimensions.
4. More variety of traps that can be put into the profession of siege engineer. Creation of tunnels to demolish walls, hay rolls that can be set on fire and placed below, etc. etc.
5 - I know that at one point it was spoken, but the creation of a political system based on counties, duchies, kingdoms, bishoprics, mercantile republics, etc. Besides an economic system that is being polished, I suggested adding to this, the royal roads, those that were the main routes between the towns of the npc's, this would not prevent the creation of the roads by the players.
They are only suggestions of a historian who considers the game with huge margin of progress, potential and above all realism.