You should integrate the heroes and also the kings into the game better than the predecessor. Heroes as well as kings should be able to be recruited into castles and / or council houses. In the predecessor, kings practically only had a representative function and could only be played in campaigns. That should be different so that you can play them in combat. The kings should also get minimal attack values. Of course, heroes and kings should be producible multiple times, just like villagers and have some special functions. I am thinking of strengthening military units in the presence of the heroes. The king would be responsible for strengthening civil units such as the villagers if he is at a certain distance from the units. That would be suggestions for the appropriate integration of heroes and kings into the game, so that they mostly not only look representative as in the old Age of Empires 2.
The Middle Ages were the time of heroes, kings, princes and dukes, so bring them here too in the game. Unfortunately, the predecessor did this far too little, with the result that we basically played a game in the Iron Age instead of in the Middle Ages. Every player who is familiar with history knew and is aware of this fact.