- Making the game a REAL turn-based game. IN RTW and M2TW, it is possible to move a little at the time to spot things or try sneaking stuff.

- Having more options like in STW and MTW when one of your territories was invaded. This way it would be possible to react to an invasion or maybe instead remain in your city and fortified it

- Reduce as much as possible micromanagement because of agents. It was fine with STW and then MTW also but the huge map of RTW and M2TW really makes this headache.

- Come back to 4 TPY system but one turn income like in STW. Was very challenging to budget your money (because fields were being taxed only in fall right) although if proven to be the case, trade could bring income every turn.

- Make commanding armies more realistic, where you virtually decided a battle plan with troops placed under subordinate commanders (not dumb ones this time please!) where it is possible to given them specific orders (eg. when signal X is given, move to point A, turn your forces facing left and envelop the enemy army's flank)

- When new order must be given to troops, use a system of couriers and reports which would take time, might be misinterpreted by the subordinate commander or even intercepted by the enemy ! No more of this god all-mighty flying all-viewing camera.

A better morale/cohesion system for units and their organization (a cohesion system such as in Waterloo, Napoleon's Last Battle would be simple and nice) Because having 100 horsemen running through 200 infantrymen without anybody being hurt or any formation messed up is completely stupid and impossible.

More realistic political governments with titles such as ministers, generals, dukes/barons/counts, royal families, important religious characters, with historical succession laws for kingdoms and fiefdoms. Thus a governor could be named for a specific region instead of having to allocated a family for every town (cities could probably be ruled by lesser administrators I guess)

A more realistic way of constituing armies where units where raised to be part of of sub-unit itself part of the main army. Also include OOB (Orders of battle) for army instead of a stack with 20 units in without any specified functions between units.

As well as developing cities with buildings, new technologies or social/military/politic improvement should become available after specific buildings are build or events happened (time required could be hidden to the player and would depend on various factors) Such as the Marian reforms in RTW but on a much larger scale and subjects.

An historically inspired logistic system and possible negative effects if armies get out of supply (desertion, disorganization, illness, etc)

Much deeper diplomatic system and strategic agents (spy network, religious agents, princesses and royal marriages, etc)