All Soldiers in Ancient Egypt (more so the Ptolemaic Dynasty than the Kushite Dynasty) used Axes as Secondary weapons, meaning that all men had an Axe with them to use if their Spear broke, or a Sickle like Sword called a Khopesh. Spears would be the primary weapon, not the Pike as shown in the Game. (Pikes were used almost exclusively by the Ruling Classes.) Swords were rare in Combat compared to the Spear and Axe, and the Axe was used as a Counter-Infantry weapon, I'm guessing against Swordsmen. It would be strange if an Axeman fought against a Spearman, for the Spear would kill the Axeman before he could even swing. They would have an advantage over the Swordsmen, though. The Britons and the Gauls alike used Axes for the same purposes as the Egyptians, and used them as a Secondary weapon. Shortswords used more often as a Secondary weapon than the Axe.. Although some would fight exclusively with the Axe, it was most common to use a Spear. The Spartans also fought with Axes, though rarely. Remember, the Celts and the Spartans fought with a Militia Force, so the weapons used would vary. As ChronA said, the Romans also used Axes, but on occasion only. It was a smaller Axe called a Pilum, and was thrown at the enemy to cause disorder among the enemy, much of a similar use to the Plumbata . Actually, most Ancient Armies had some Axe units, but they would be very rare, as Axes would only be used in specialized combat. The Chinese Imperial Guard (Han Dynasty) used only Axes and were famous for using very large ones, like this:
So yes, it does make sense Historically, because all the Civilizations I discussed in the latter paragraph have used Axemen in their Military. Of course, 0 A.D. doesn't have the Han Chinese as a Civilization, but I just wanted to share that interesting morsel of information. In case you wanted to know, my two favorite Ancient Civilizations are the Hasmonean Dynasty Jews and the Brythonic Celts. And my favorite Weapon/Tool is the Axe. That is the main reason why I wrote this is to get some Axemen into the game. Although there are some Axe units, like Kushite Temple Guards, and Hyrcanian Axe Horsemen, I just wanted some Civilian Infantry. Thank you for reading.