The computer games Europa Universalis IV, Crusader Kings 2, Imperator: Rome, and others by Paradox Development use something like this by splitting up the map i

The computer games Europa Universalis IV, Crusader Kings 2, Imperator: Rome, and others by Paradox Development use something like this by splitting up the map into irregularly-shaped provinces that can have a variable number of connections with other provinces (including tactical considerations such as penalties from river crossings) and have different travel speeds for armies based on the sizes of particular provinces. A simple visual example of somebody looking at the diplomacy view of their country in EU4: https://i.imgur.com/hfI8NnM.jpg https://i.imgur.com/hfI8NnM.jpg