Heavy infantry are placed on the flank where the relief force is expected, while battering rams attack the opposite wall. This lets one group contain the field army as another threatens the garrison, which must still man the walls. Supporting troops stay outside easy wall-fire range until needed. The Roman force refuses to chase the relief column while the siege is active. Later, the Carthaginian commander chases skirmishers while the main army is destroyed, showing how a divided defence gets worse when a commander loses sight of the main fight.
Notable Point · 59:45-1:10:28
Separating a garrison from its relief force
The siege plan sends heavy infantry toward the expected relief force and rams toward another wall, splitting the defenders between the field army and the garrison.