Cortes had a lot of military help from other nations such as the Tlaxcalans, true. Pizarro, not so much. The Incas weren't as universally hated as the Aztecs an

Cortes had a lot of military help from other nations such as the Tlaxcalans, true. Pizarro, not so much. The Incas weren't as universally hated as the Aztecs and in fact their state lingered on for decades (a rump one around Vilcabamba) after the initial conquest of Cuzco. What certainly helped him was something unintended - the bloody civil war of succession between Atahualpa and Huascar that sapped a lot of strength and cohesion from the empire. Contemporaries described the main battlefield of that civil war as "full of bones as far as an eye can see".