The Woldan wrote...
Not really, two handed swords were able to cut through chain mail quiet easily (arrows were able to penetrate it).
No.
Sword weren't able to CUT a chainmail - they would dislocate some rings with a blow, and would hurt the wearer by the concussive strength, but unlike in Hollywood, you don't slice through metal rings effortlessly. Of course, it happened that some very powerful blow would smash enough rings to penetrate the chainmail, but most of the time the armor absorbed most of the damage - which could be enough to have the soldier barely grazed, or not enough and have him killed, but anyway it increased a lot his survivability.
Samely, standard arrows had a lot of trouble penetrating the chainmails - it's why they designed special arrows with small heads to slide between the rings.
In fact, two handed weapons have been invented to give them some extra power to be able to defeat enemies in platemail. Its hard to kill somebody in full platemail with a sword? No, its not. A full power swing to the helmet and the neck is broken, a decent hit on the arm and its broken too, despite the armor.
A full swing to the chest might not penetrate the armor but it will dent the armor and break the bones behind it, your enemy will also have troubles to breathe in a completely dented armor.
Of course, blunt weapons worked even better (hammer, flail)
Actually, two-handed weapons were more designed about range than extra power. Two-handed swords were more about cutting the haft of polearms (though yes, they were ALSO designed to penetrate armour), and most "armor-piercing" weapons were maces, warhammers, halberds and the like (blunt weapons to conduct the energy through the rigid plate or the flexible chainmail, and piercing weapons to concentrate the power of the blow on a small area and get through the armour), many of them being one-handed weapons.
And again, of course that you COULD kill someone in armour (or else the battles would never end...), but it was clearly not as easy as you describe "just land a hit on him and his armour will be crushed !". If they invented such heavy and expensive armour, it's because they actually worked. You required a lucky heavy blow to harm someone wearing one, which isn't easy to do (they ARE fighting you and not just laying low waiting for the strike after all).
As a testament of how efficient armour were, they made shields obsolete with time. You don't throw away your shield if your armour doesn't do the job well.