Or, you could...you know. Wear them on your belt. Most war blades actually didn't have sheathes, since you would only use them so rarely, and wither have to immediately repair them afterwards anyways or...be beyond such concerns.

But yes, I know such things are possible, they're just wildly impractical. Even your example is still clumsy as hell, as the main issue is that drawing from your back is difficult and time consuming, things that are not exactly ideal in situations where you need to quickly procure a weapon.

Although the Ottomans had a neat workaround. Spring-loaded sheathes. Though that was, in part, due to their blades being so curved, but still a neat way to back draw. Probably even more dangerous though. This IS the same culture that had invented the whip sword, after all...

@Anima So...Should I be worried that I haven't heard from you yet or...?