Regarding different historical swords. This is a really informative, pretty easy to understand article. It talks about the grade of steel different "famous" swords had.
http://www.tameshigiri.ca/2014/01/21/razor-edged-3-comparing-metallurgy/
All three sword styles covered here were using extremely sophisticated techniques to attain edge hardness that would rival modern steel.
I'll just add as well regarding the article cut/paste on the last page regarding the Samurai and their weapons.
The spear was not their primary weapon, the bow was, then the spear, then the sword. The reason is simple and the article pretty much nails it. The spear, or more specifically the pike is the most dominant hand to hand military weapon of the pre-gun powder age. The Yari, which was the spear used by the Japanese in this period was more pike than spear. The Ashigaru (the peasant conscripts) were fielded en-mass with Yari which would have been 15-20 feet long.
The sword had a brief stint under Rome, but that was more a reflection (I think anyways) of the enormous bureaucratic, administrative, and logistical machine that was Rome. Rome could have conquered what they did with just about any stabby or slashy weapon.
The Macedonian phalanx is basically the first instance of western pike combat. It's no shock that almost 1500 years later at the onset of the gunpowder age, pike blocks again ruled the battlefield. A wall of pikes wheeling together and holding cohesion is basically unstoppable frontally and properly drilled is difficult to flank.
Rome killed the Macedonian phalanx in Europe when they defeated Macedonia, but the Macedonia they defeated was a shell of its former self. Made up mostly of undrilled levies. A far cry from Philip II and Alexander's elite professional phalangite corps.
I'm totally outing myself as a massive nerd with too much knowledge of unpractical things!