How light infantry, missiles, and cavalry counter Roman heavy infantry

The Roman force contains several units of principes and hastati, while the Carthaginian army lacks comparable heavy infantry. Town militia cannot meet those troops on equal terms, so greater numbers and a mix of light infantry, skirmishers, and cavalry are required. The light infantry forms in double lines to create defensive depth and absorb the Roman impact. Cavalry serves as the offensive sledgehammer, using mobility and weight on the flanks to counter the Roman infantry advantage.