Unfortunately due to personal circumstances, this AAR will be put on hold for the forseeable future. We will restart at some point, but it might not be for a month or so. Sorry to disappoint any avid followers, but I promise Ash and Will *will* be back
Those are the only 'mods', as far as I know. There aren't any mods in the sense of changing the setting to Mordor though, if that's what you're looking for =p
Press 'S' once to view your current supply chains, press it again to view your predicted supply chains next turn. That should give you a good idea of where supply originates from, but if it doesn't;
HQ's give supply. If they are in low supply (1-5), such as near a town, they will grant 8 supply. If they are in high supply (6-10) they will grant 10 supply. Supply decreases by 1 for each square away from the originator of the supply- so if a HQ is giving out 8 supply, the highest possible supply for nearby units is 7, then 6 for units slightly further away, then 5, etc. The local geography of an area can have further impacts on how supply decreases over space- mountains, lakes and rivers all impede supply, while roads ensure good supply.
Cities, mines, towns and docks all give (varying) supply as well. It works exactly the same.
I've now writted the word supply too many times and it's lost all meaning, but I hope that helps =p