I bet it was far more likely logistics considerations than simple Just-so stories about culture. (and we know Rome's order of battle; Hannibal would have had a much foggier picture)

That said, Hannibal's cavalry commander 𐤌‬𐤄‬𐤓𐤁‬𐤏𐤋 is supposed to have said (and it would be in keeping with the cavalry bias towards action; compare Alexander) the Carthaginian equivalent of "vincere scis, Hannibal; victoria uti nescis" (you know how to win, Hannibal, but not how to exploit victory)