How and why was he able to get help from some of the indigenous peoples?

Indigenous peoples, also known in some regions as First peoples, First Nations, Aboriginal peoples or Native peoples or autochthonous peoples, are ethnic groups who are the original or earliest known inhabitants of an area, in contrast to groups that have settled, occupied or colonized the area more recently. Groups are usually described as indigenous when they maintain traditions or other aspects of an early culture that is associated with a given region. Not all indigenous peoples share this characteristic, as many have adopted substantial elements of a colonizing culture, such as dress, religion or language. Indigenous peoples may be settled in a given region or exhibit a nomadic lifestyle across a large territory, but they are generally historically associated with a specific territory on which they depend. Indigenous societies are found in every inhabited climate zone and continent of the world except Antarctic

definitely a for sure. ill see and update if i get the answer

they both built pyramids.