What country or group had the greatest warriors of all time.?

Who were the greatest warriors of all time, the samurai? the spartans? the romans? the british?the persians? and many more. all of the countries or clans/bands that used swords, bows, armors, castles. sheilds, battering rams, horse charges, spears. stuff like that. if they all had a war, who would win,not judging by numbers, but by training, tactics, weaponry, and leadership. this is one quistion i have always wanted to know.