The physics run something like this.
An axe has a heavy weight at the end of a long stick. Chops well because you can concentrate all the force in that one spot ... that's rather like an AK.
A sword might have the same overall weight, but it's distributed much differently along the length of the blade. Assuming that the handle's also heavy enough to counterblance, it can change path very quickly and still hit pretty hard. Not so hard as an equally heavy axe, but it's much livelier in the hand.
A Siru's got a more even weight distribution than a dedicated chopper like an AK or GRS, and tends to be lighter for the same length as an AK or GRS too. So it's not going to hit as hard, but might be more accurate and will be swifter to swing. It's livelier in the hand too. The AK or GRS will hit like a ton of bricks (rather than the Siru's 1/2 or 3/4 ton of bricks), but you'd better want to hit what you're aiming at. It's not gonna be stopped in mid-swing, or diverted very easily.
A khuk will also cut more efficiently, depending on the bend and belly of the blade itself - the more curve, the more the edge is forced into a push-cut on impact, giving some slice to the hit. This is the Khuk's secret physics advantage ... the design draws more steel through the target for a given "hit" than a straight blade; the slicing cleaves the material efficiently. much more efficiently than straight edged hacking ...
So that bend and belly will, once you learn to cooperate in a push cut, give better results than chopping with a straight blade of the same size and weight distribution. Combine a bent blade with more weight forwards (as in GRS or AK), and that effect's amplified.
the carvings are to beautiful.
