Tell that to Pizzaro. Read about the battle of Battle of Cajamarca. Spanish forces armed with iron weapons and superior skill could and did defeat indian forces 10 and 20 times their number. The casualty count were unbelievably lopsided. It happened on several occasions. Indians had no concept or ability to operate against a European army.
It’s trendy these days to belittle and blow off the accomplishments of the Spanish soldier in those days, But that’s mostly revisionist anti western thinking.
The Conquistadors were maybe 1 generation removed from the Reconquista. They had fathers uncles even older brothers who had fought the Moors
They were tough nasty guys looking to make a fortune with no good job prospects at home other than fighting the French and or hiring out to some other European power. The tactics and weapons they had were too much for Aztecs Incas and others. Horses, iron and leather armor, guns, crossbow, war dogs, steel swords, Lance.