Why was Carthage so powerful even though they relied on a mercenary army

Cartage was verywealthy because she controlled the coasts of north-western Africaand southern Spain and controlled the trade between this part ofthe western Mediterranean and the eastern Mediterranean. Shemanufactured low quality goods which she sold in Africa and Spain.She bought tin, which was needed to make bronze, and silver fromSpain and sold it in the eastern Mediterranean, where she boughtquality manufactures. With the wealth this generated, Carthage wasable to afford thousands and thousands of mercenaries. She couldpay for an army whose size was second only to Rome. Carthage reliedon mercenaries because her citizens did not fight in the army. Sheneeded them to stay at home to continue manufacturing the goods sheexported.After losing the FirstPunic War against Rome, Carthage struggled to deal with a revolt byher thousands of mercenaries (the Mercenary War). Carthage releasedthat she could no longer afford to rely on mercenaries, bothpolitically and financially. Although the Carthaginian army of theSecond Punic War still had mercenaries (Celtiberians from centralSpain, Mauritanians and slingers from the Balearic Islands) thebackbone of her army were now conscripts from western Libya andfrom the newly conquered southern Spain. In this war Carthage alsorelied heavily of the Cavalry of her allies from Numidia (in modernday Algeria).