Oh! Albireo. I have a solution to that.

A lesser known invention of some excellent use. Exceedingly simple, but it allows massive weapons to be carried on the back- Something that actually makes sense, given that they would drag on the ground if worn at the hip. Many sheathes for blades that size were actually only partial sheathes. The lip still locked into the chappe to keep it in place, but for about half of the sheathe's length there was no outer edge, meaning you could pull the sword -part- way out and then simply pull it from the side, no need to draw it out the entire length and break the laws of how long arms are. It was fairly popular for bastard swords and greatswords, due to their general blade length. Admittedly, this also meant extra maintenance on the blade and sheath due to them being partially open to the elements compared to full sheathes, but it still made larger weapons easier to draw.