Stop treating IG messages as instant messaging.
Simulate messages actually being carried from the sender to the recipients.
As dedicated messengers move much faster than nobles and their retinues, let's give messenger a virtual 24 hr pool. Meaning that messages within a few regions will still be delivered on the same turn. Messages travelling three and more regions away will arrive with a delay of at least one turn. Messages across the continent will take weeks to arrive.
What does this accomplish apart from irritating the haters?
Huge realms become a real pain to defend which levels the field somewhat for small agressive kingdoms.
Marshals become actually important as the general will not always be able to coordinate separate armies efficiently.
Super-active realms no longer get a massive upper hand due to coordinated moves across the front 10 minutes before the turn end.
The game becomes more about strategic planning and mind games for generals and more about difficult on the fly tactical decisions for marshals.
