Some weapons really need a little better modeling. Urumis or chain whips don't really fit... they'd be slower, have a larger contact area and, for urumis, be edged weapons. If they are meant to be leather whips with metal tips, they're heavier than they ought to be. This increases the main problem with whips: for impact calculations, the game assumes the entire weapon is moving at ludicrous speed; reduce the size to single-digit figures and you have almost realistic behaviour. If we take them at face value, fine wire (twisted or braided like rope?) ending in a solid tip would take the most sense, but damage calculations still assume the thing is rigid.
DF currently isn't trying to match overall real-world effectiveness, it just attempts to simulate single hits. Being balanced towards the tip is a straight-up benefit at the moment as the higher velocities are modeled, being less controllable (slower to reocver, less suitable for parrying etc) isn't. So some weapons like mining picks are considerably better than they ought to be, even without modeling artifacts like we see in whips.
Also, could we PLEASE stop referring to whips as lightsabers? They don't sever things easily, they aren't particularly lethal, they crush/chip rather than cut/burn. 40mm cannon rounds would match the statistics (roughly 1kg of metal hitting point on at supersonic speed; thankfully the game drops penetration calculations if there's no edge) but they're just what they are: Whips with a modeling quirk that puts 10-100 times the weight it should into the blows.