well it depends on which natives we're talking about. the aztec and inca, or the nez perce etc etc etc
if the aztec had recognized the whites as a threat from the beginning, and small pox was not a factor, then there would be no spanish speaking central america today. theyd have no ability to project power or establish a base of power in central america. their guns were shit, and bows and arrows were better. the spanish didnt even use them that often. the horse was a legit factor, but how would they get enough over here to defeat an empire of millions? the same would be true for the inca, and there, the horse would be less of a factor. calvary charges in the andes? meh.
look up USA settlements in the upper midwest prior to 1850. they dont exist. why? because the comanche owned that land. any time whites came in, including the US military, they got killed. the revolver pistol in the late 19th century was the only thing that changed this. because of that, the US military could stay on their horse and fire multiple shots, rather than stay on the ground with rifles and get raped.