People’s tactics uses the scenario scenarios/2PL_Two_Rivers.pt1 to determine the type of units and other game rules for random scenarios; if you back up this file and then rename, say, 2PL_World_War_One.pt1 to have the name 2PL_Two_Rivers.pt1, random scenarios will now have World War I units (no tanks until this technology is purchased with political points, etc.).
Cool way of getting more variety out of People’s Tactics’ random scenarios.