That's not entirely accurate actually, as with anything there were infact varying grades of quality in European bladed weapons, particularly things like the Long Sword. The big difference was the sheer number of troops equipped with such weapons, where as only noblemen could use them in japan, in Europe every soldier had blades, meaning the demand and distribution required was so high that a multi year process for one sword was in-viable. Additionally, if you look at the uses of them, long swords were used mostly for duels against other people in full plate armor as opposed to slicing through lightly armored foes. While they both fit into the category of swords, they have completely different primary functions, the Katana was made to kill as a primary, the long-sword was created to duel as a primary.
Additionally Berserkers were classified as 'elite' status warriors, able to take down dozens of men alone, with a weapon that was designed to be a joke but turned into an effective killing device (aka the Clay-more) and the German Zweihander wasn't made for killing men, it was made for killing horses that had troops mounted on them.
History, read up on it.
That aside, looking forward to getting my firebug back, I do love me some bbq
-Edit-
Also just looked at the model for the sword, it's not a true zweihander but rather a flamberge, the waviness of the blade gives it away and it was designed like that so that if some one parried the blade it would send unpleasant vibrations through their arm, causing additional fatigue.