Roman historians write that when Hanibal's troops were victorious on the battlefield against the Romans, they looted their dead adversaries' chain mail.

Were these troops unarmored because they were mercenaries and Habibal didn't spend money to equip them, or did they already have the linothorax armor which had been used by Greek and Carthaginian troops for centuries and chose the chain mail instead?

Was it due to the change of theater? Was the hot African sun better suited to linen-based armor than metal armor? Did it only become bearable when Hanibal's troops got to Italy and it was cooler?

Does chain mail offer dramatically better protection than Linothorax? What would the weight difference have been like?