Also for medieval TW games:
A more descentralized gameplay.
Your should only have direct control over the cities your main family members ( e.g your king and his sons ) control. Every other region, ruled by the other nobles, should be near authonomous, but still indirectly ruled by you.
For example, if you wanted to recruit troops from the region Gascony , you would choose "Call vassals from Gascony" option and set a rally point for their troops. It would take some time for 'em to assemble their men, but then they'd march to the point you sent them to. Of course, depending on the noble controlling the said region, they could refuse to obbey their king if their loyalty was low enough.