In latin, Punic means 'Phoenician', a seafaring civilization originating from present day Lebanon, who specialized in trading/selling the world's most expensive commodity, the color purple extracted from sea shells called Murex. Based in Carthage, present day Tunisia, they were Rome's ONLY rival for the Mediterranean world.
Phoenician civilization's greatest commander, arguably the best commander EVER, was named Hannibal. His goal: slaughter the Romans by taking war directly INTO the very heart of Rome ITSELF.
He did this by dominating Spain, located in Italy's rear. He crossed the Alps in the winter with trained Elephants, having them brought over the Mediterranean Sea in rafts, upon their arrival in Spain, Hannibal's coalition began foraging south picking off Rome's northern alliances. ALL THE WAY TO THE CITY OF ROME ITSELF!
Rome's best commander, Africanus Scipio was defeated EVERY TIME by Hannibal, but the Roman's learned to use Hannibal's warcraft against him. Hannibal's superior warcraft actually taught the Roman's HOW to defeat him.
Why study the Battle of Cannae? The battle is studied to gain extraordinary tactical advantage procured by Hannibal's strategic, tactical warcraft. Upon engaging the Roman's on an open flat field, Hannibal anticipated to draw the Roman center by collapsing or folding inward Hannibal's forward moving center, enveloping the entire Roman column. When the Romans were hemmed in on all sides, Hannibal's men were able to slaughter the Romans in a devastating blow to domestic morale.
Battle of Cannae YouTube https://www.youtube.com/watch?v=CQNCGqfjaBc
Lesson: Mass is a liability even in favorable terrain. Superior strategic, tactical adaption is the baseline for every conflict.