Here's an idea I've got about supplies in
Dom 3: The use of
supply lines to get supplies from one province to another.
To illustrate, let's say you're playing Jotunheimen. Your capital produces 300 supplies and uses 10 for the units in it, leaving 290. A neighbouring province produces 21, and the province your army is in produces 4. The problem is that it requires 192 (don't ask how you can have such a huge army and only three provinces, 'k, I'm just providing an example
).
So the army in the third province needs 188 supply units to avoid starvation. The neighbouring province has 4 supply units it's not using, and sends them over. The capital has 290 supplies left-over, and easily manages to cough up the 184 your hungry army needs.
Maybe there should be a delay before supplies made it to armies, and maybe some of it would get lost along the way. For example, if Jotunheim is giving 100 supplies to a province five provinces away, less than 100 would reach it?
I'd also like it if you could prioritize armies for supplies with settings scuh as "Keep this army fed when possible".
Also, it'd open for new strategies. Unimportant provinces could suddenly become very important as taking them cut off supply lines and left armies starving.
In addition, there could be spells, items, upgrades, etc. based around the supply lines.
Finally, spies could have an "Harrass caravans" order, which decreased the amount of supply units an army received.