The 75mm and 76.2mm cannons say they should use the light rifle's damage when used against modern units (XTRO:1945, p.28), but that means they actually deal less damage than the smaller calibers (which are equivalent to recoilless rifles) due to rifle/cannons having -3 damage against BAR 8+ (TO:AU&E, p.150). Is this intentional, or should the damage reduction for rifle/cannons be ignored in this case?