The Third Fitna combined provincial uprisings across the Umayyad caliphate with the Abbasid Revolution that ultimately overthrew it, fought in different regions at different times with a final purge of the Umayyad family at its close, and the scholarship follows that sequence of events narratively rather than tallying deaths across it.
What would resolve this A historian's combined accounting of the war's provincial battles and the Abbasid purge of the Umayyad family that followed, or a source critical study of the surviving casualty claims.
OpenEarly Islamic history, Abbasid history.Hugh Kennedy, The Prophet and the Age of the Caliphates: The Islamic Near East from the Sixth to the Eleventh Century