[Gandalf Parker]

There are 4 ways to effect changes to the game.
1) command line switches
2) map commands
3) mod commands
4) directly editing the files

To add supplies you can use the command switch of
--supplies X Supply multiple 50-300 (default 100)

You can use map commands to design a pretender with lots more nature magic than would normally be allowed. Have all your starting commanders start with supply boosting equipment. Or add a supply boosting magic site to your capital.

You can use mod commands to boost your pretender or make your units require less supplies, or give your nation early access to supply-boosting spells.

Direct editing I wont cover.