This is just nonsensical. The main reason why the Spanish were successful was political: the Incas (which means "rulers") had forged their empire with violence

This is just nonsensical. The main reason why the Spanish were successful was political: the Incas (which means "rulers") had forged their empire with violence and the tribes they subjugated were only too happy to get rid of the Incas, so collaborated on a case-by-case basis with the Spanish. In addition, the ruling family (i.e. the Incas) was quarrelling amongst each other, with some of them collaborating with the Spanish to get rid of the other side of the family. The idea was: (1) let the Spanish do the dirty work of getting rid of the other side, and (2) then get rid of the Spanish. Part 1 worked very well, Part 2 ... not so much. It's pretty clear that Pizarro was in a fairly weak and tenuous position. If the Incas had worked together, rather than fighting among themselves, they would have defeated Pizarro easily.