Some find Weart's use of sources questionable, particularly regarding the conflicts in antiquity. He excludes the earlier wars of Rome, including the Punic Wars, bu stating that there are no primary sources and no reliable secondary sources, such as by a historian who could understand Punic, from Carthage, which makes it impossible to determine the exact form of government at the start of these wars. However, he uses Xenophon for other conflicts, who has also been doubted as a reliable source although not for the same reason. Also, many modern classicists agree that Rome and Carthage were oligarchic republics, "which suggests that excluding them was a largely arbitrary judgment that just happened to leave Weart's central claim intact." However, Weart states that there have been some wars between oligarchies and so they would add to his list, not disprove his statement.