Alexander/Mercenaries

Libyan
Javelineers, swordsmen, spearmen and light cavalry. And the odd chariot.

Greek
Mostly hoplites, archers, slingers, as well as 2 sets of cavalry - Tarantine and Thessalian
 * Mercenary strategos
 * Mercenary hoplites
 * Mercenary slingers
 * Mercenary toxotai
 * Tarantine mercenaries
 * Thessalian mercenaries

Illyrian
Light cavalry, javelin cavalry, hoplites, swordsmen, slingers

Thracian
Swordsmen, archers, javelineers, javelin horse

These units have a food ramp.
 * Balkan horsemen, along with
 * Balkan skirmishers,
 * Balkan axemen and
 * Balkan clubmen

Eastern
All manner of units - light cavalry, heavy cavalry, sparabara, archers, etc

Arab
Archers, spearmen, skirmishers, slingers, camel and horse cavalry

Indian
A vast number of units - longbowmen, archers, macemen, axemen, elephants, chariots

Nomadic
These units have a Food ramp.
 * Scythian Bowmen
 * Scythian Warriors (armed with axes)
 * Scythian Light Lancers
 * Scythian Horse Archers
 * Scythian Renegade Noble (axe cavalry)

Celtic
Mostly infantry, but also have good cavalry. Not armoured, but highly varied.

Italic
Swordsmen, spearmen, skirmishers.