Egypt during the time period was ruled by Macedonians & Greeks. Egypt at this time was actually one of the Greek Successor Kingdoms, a remnant of Alexander the Great's Empire. While the rulers went "native" the army was mostly made up of Macedonians & Greeks, and were armed and fought like other Greek and Macedonian armies.

The Carthaginian Sacred Band did not exist during the game's timeframe. They were disbanded about 300 B.C.

The Gothic heavy cav is anachronistic. The Goths did not emerge as one of the more powerful Germanic tribes until the Late Roman Empire. During the game's timeframe they were unimportant and far from Rome's borders.

The area that is today Belgium and Holland was not controlled by Celtic tribes originating in Britain. The area was controlled by Belgic Gauls. That territory should belong to the Gaulish faction rather than the Britons.

Chariots were obsolete even long before the game's timeframe. They had been made obsolete by cavalry which easily defeated them. Some factions in the east still used them, but they weren't anything near as powerful as they are portrayed in game. The primitive Britons also used them, but they also weren't as powerful as portayed in game. The Britons used them as a vehicle to ferry nobles into battle, and just as quickly out of it if things went sour more than anything else.

Gladiator armies: They didn't exist, at least not as seperate units on the battlefield. They weren't a part of Roman armies. The Romans conscripted some slaves, gladiators and other riff raff into a legion once after Cannae, but they were trained and equipped just like other legionaries. In slave rebellions gladiators sometimes took part, but they wouldn't have been segregated by gladiator type and armed in that fashion on the battlefield. Gladiator training and weapons were designed for fights in the arena, they weren't well suited for the battlefield.