Civ IV/III domination wasn't purely a focus on military, it was more to represent your Civilization controlling so much of the land and population to make global influence a certainty. While you may achieve much of that via military might, you certainly also acquired a good deal of it from simply claiming land and growing cities. Heck, there was even a Realms Beyond challenge that called for achieving a Domination victory with "always peace" enabled.
"Conquest" was an entirely separate victory condition that depends on eliminating all rivals. Civ V seems to discarded Conquest and made Domination the military victory type. Civilization VI is continuing the trend.