Christian civs

These factions are near-unrivalled in defensive might, fielding powerful knightly cavalry but often lack Wonders, so being a military power is their primary focus. These factions emphasize heavy infantry and elite cavalry, but have rosters heavily affected by your policy choices: for instance, establishing a Monarchy allows training armies with knights fighting in the Latin style, excelling at crushing infantry but oft requiring complex micro-management due to their being somewhat uncontrollable.

Nomad civs

The scourge of sedentary agrarian peoples throughout the world, these horse-riding peoples don't just eke out pastoral lives - they are expert raiders too, excelling in warfare on large, land-based maps but don't do so well elsewhere due to a lack of proper naval assets or marching men. This aside, they all have different perks: Khamag Mongol and Qara Khitai focus on teching up to receive professional units, while the Polovtsy are early rushers with a diverse range of different mercenary units.

Muslim civs

Muslim civilizations favour mid-game victories, through use of hybrid strategies, being capable of both early raiding, or booming and during the mid-game. Their unique access to advanced Pedagogics upgrades often make them a cultural force to reckon with, being capable either of winning Wonder races, or early-game rushes: the only problem is that they often lack strong defensive infantry, although Hindustan has a decent foot component for her armies.

South Asian civs

Culturally diverse yet at the same similar, the South Asian nations of Temüjin all share common strengths and weaknesses: they often train armies of light infantry and elephants, but are apparently deficient in heavy infantry or equipment. However thereafter their paths diverge, with Hoysala and Rajputana excelling at booming, whilst the Dai Viet and Khmers suit gameplay on smaller maps, relying on their niche units to exploit the weaknesses of more conventionally built armies.

North Asian civs

The nations of North Asia (dominated in the main by China) are the most advanced in the world, excelling at diplomacy to buy their way into Wonder victories or Territory victories. While these civs' best shock cav units are built to resist horse archer civs, not all of them can aspire to greatness - and achieve it. Dajin is strong as much as she is versatile, while Goryeo, tends to be a weaker nation, heavily dependent on turtling to stay alive.