The vanilla version AoW3 comes with 6 (or 9 with both DLCs) playable factions or races, including the basic tolkienesque stuff like Elves and Orcs, and also some new ones. While they are accustomed for specific terrains or "themes" and damage types (Frostlings for arctic/frost damage, Draconians for volcanic/fire damage...), other aspects of strategy are levelled, as they have very similar sets of units. The mod uses less playable races with more diversity. The removed races will likely be later added as dwellings; some individual units can still be recruited (e.g. the Draconian Archer and Priest in the Dragon dwellings) or found as guards of visit sites.
At the beginning of a game, the player can usually build three basic (t1) units: an irregular, an archer and a melee infantry unit. The player receives more options with the development: two t2 units are enabled by the Armory upgrade (a cavalry unit and one racially specific type), a priest unit is available from the temple.
Humans are a versatile faction with the full spectrum of available units. Earlier units are more defensive, later ones more offensive. They are roughly based on a late medieval setting: basic (t1) infantry with spears or crossbows, heavier (t2) units with armor or horses, with a fully armored Knight as the elite unit (t3). The archer (Crossbowman) has a shield for defence and their offensive t2 infantry (Man at Arms) is equipped with a polearm, making it effective against birds and cavalry. Their Priest deals Spirit damage. They dislike Volcanic and Subterranean terrains and feel good in fertile lands.
Dwarves are the Rome of the game, focusing on defence and a well-equipped heavy infantry. The t2 Guard unit is meant to be the best defensive unit among the basic sets with about 14 defence rating. The elite unit was preserved in its original role, with only cosmetic changes applied (e.g. renamed to Paladin). Their Forge Priests deal fire damage, which also enhances the Paladin's attack. As they prefer colder and mountainous areas, they dislike only the Tropical climate. The disadvantage of their superior unit pool are the cost, and also the inability to use Terraforming to improve morale of their cities.
As in the vanilla game, Elves focus on ranged combat and mobility. They have only one unit in the basic set without a ranged attack - the Satyr, t1 spearmen. The original elite unit has been replaced by the Farseer, a t3 battle mage. They have two archer units: a low-cost t1 Archer with Forest Concealment and an armored t2 Ranger, both receiving racial upgrades. Farseer and Fairy deal Shock damage, the priest unit (Dryad) has the versatile Fairy Fire attack. They are quite choosy for terrain, disliking Arctic, Volcanic and Subterranean. Satyrs, Fairies and Dryads count as Fey, with a bonus for Wetlands.
Orcs focus on offence, lacking a spear unit and a truly hard-hitting archer in their basic set. Instead, they employ a t2 monster (Brute), which can demolish walls and may receive the Fearsome ability. The t3 unit has been replaced by the Devastator, a heavy cavalry unit mounted on mammoths, bears and other beasts, with the Guard Breaker ability. Their archer and priest units are racially Goblins, with a bonus for the Wetlands terrain. This Goblin Witch Doctor attacks with the versatile Bane Fire ability. Orcs prefer Barrens and dislike the Arctic climate and Water.