I have a BattleSim map that helps.
Its a very tiny 10 province map providing the variety of terrains. Editing the ascii text file of BattleSim_v3.map makes it easy to set two nations next to each other with specific armies so that you can test tactics or how the game does things. And then you can either quickly easily start another game with the same settings to see if the results are the same, or edit the .map file to some small change to see if that makes a difference.
http://www.dom3minions.com/utilities.htm