You really think the spathion is so much better than eg, the broad short sword for an archer?
Sure, you get extra slice and range, but the 28p on the broad short sword and the speed is a godsend.
Who's gonna catch you? Guys in armour or shielders
Are they gonna be faster than you? Yes
Are they going to gank the fuck outta you? Yes
So what you want, is a short stabby sword, that can pierce plate, won't bounce off armour and has enough speed to make up for low wpf! And length doesn't mater cos you can't back peddle spam with arrows on your back!
The spathion as an archers weapon would be if you're getting chased down by guys in mail.