On Couriers

This campaign is largely an excuse to fulfill two dreams at once; run a PBEM campaign, and run a strategic level game to generate organic battles for the tabletop.  Rather than a long string of perfectly balanced encounters, the hope for this faux-war is that we'll see a lot of asymmetric battles.  Maybe even battles between armies with less than perfectly balanced compositions.  As the attrition occurs, armies will struggle to maintain a fully effective force...just as happens in real life.

As to the PBEM nature of the game, this choice was driven largely by a desire to make the game as easy on the players as possible.  They are Kings in Salons, exercising all of the top-level decision making, and leaving the gritty details of the execution to subordinates.  That means that they will rely largely on the dispatch of messengers to ensure their will is carried out.

The most obvious expression of this game-design is that generals will be given the broadest  of orders.  "Capture Gwareth, and leave a portion of your forces there to screen a march on the City of Nightmute."  The umpire will do his best to follow those orders to the letter until ordered otherwise.  Some discretion will be required, though, as the general might take a detour to smash a relieving force before investing beneath the walls of Nightmute.

Less obviously, players will have to assign a courier to deliver messages to allies. At least during the campaign season.  That will take time, and there is a chance the message doesn't make it through - just as happened in history. If it's really important, they should send two messengers. The umpire will track messengers backstage so that players cannot see who is sending messages to whom, nor which generals have had orders countermanded.

Of course, players do have other means of communications at their disposal, as players of No-Contact Diplomacy and microphone-free Minecraft can attest.  For example, every player will be able to see the results of army moves at the conclusion of each phase.  As armies march forth and navies set sail, they will signal their intentions to all and sundry.

We will pause at the conclusion of the Late Fall phase, and during the long Trossian Winter, players can once again communicate freely until the start of the next campaigning year.