Cubans and Puerto Ricans have nothing to do with Aztecs, but nothing at all. And I guess neither Brazilians. At least the Indian population in Cuba was completely exterminated by the Spaniards, Old World diseases, etc. Spanish, African, their mixture, and 1% Chinese is what you find in Cuba.
Well one group where conquerers and explorers always fighting, the other where throwing rocks at each other and sacrificing people that were captured in territorial squabbles. Of course in reality someone said it earlier, who ever had the best training. I'm NOT a believer that it matters who is what its more a matter of what is who.
The Native Americans and Mongolians are probably the best tribal fighters as groups, this is not to discount China but their best fighters were Monks not tribes, Japanese Samurai's would be the most dangerous IMHO.
Anyway, don't know who where best but the Vikings travelled, drank, ate mind altering mushrooms and raped. So at least the Vikings had more fun
Aztecs were a Native American nation from Mexico. They no longer exist. The Aztecs that survived the Conquistadors and other Native Americans eventually interbred with the Spanish.