Okay. All cutting weapons can be categorized by their three major functions: choppy, stabby, and slashy. Lots of cutting weapons could do more than function. For example, some swords were designed to have a stabby bit at the end and a slashy bit at the edges. Your fighting style will be greatly influenced by what function you intend to use at the moment. For example, if you wanted to stab, you would thrust the tip of the sword towards an unarmored bit of your opponent, like the throat or the eye. If you wanted to slash, you would kind of swing the sword across, catching the edge of the sword on the chest or legs or arms. If you wanted to chop, you'd have to swing the sword down like a cleaver. All this is being done as your opponent is trying to do something similar to you, probably. Therefore, human cutty thing operators (swordsmen) are trained to make moves that keeps the sharp parts of their swords as far from their own bodies as possible, so that their opponents would need to reach into the place where the sword is moving around in order to do any damage of their own. Therefore, a swordsman creates a zone of fucking death (ZFD) of arm length + effective sword length. (AL+eSL=ZFD).

Now that you know this, you can begin to see why the Batleth is a fucking stupid weapon designed by and for morons. The slashy bits have an eSL of the edges of the Batleth (which is curved away from the opponent, because fuck winning) and the choppy bits are in the center of the damn thing, giving it an eSL of basically zero. So the ZFD ends up being arm length plus half the length of the weapon!

But wait, that's only half the problem!

Many human sword-swinging cultures spend a lot of time thinking about defense. In cultures that primarily rely on choppy swords, that means wearing plate armor (usually). In cultures that primarily rely on stabby or slashy or stabby-slashy swords, that often means carrying a shield of some kind. Klingons, who tragically seem to suffer from testosterone poisoning, were all "fuck that, shields are for pahtaks" and decided to do without. Well, here's the thing about human cultures that didn't use shields: they wielded swords that were, like, super fucking long and ridiculously heavy (two common characteristics of choppy-type swords), and they did it while wearing big heavy suits of armor that hopefully protected the most important shit like your arms and legs and face. Which meant that the ZFD was ridiculously wide, and that if anything got into the ZFD, they'd have a hard time damaging anything important.

Conclusion: the Batleth is a ceremonial weapon designed to look cool but not much else. A squad of Klingons can likely be defeated in combat by a Roman legionnaire, a knight in plate armor, or possibly even a bravo with sword and buckler.

Extensive use of the Batleth, and the amount of importance Klingon culture obviously places on the Batleth and the amount of time they spend learning and practicing Batleth combat is proof, to me, that the Klingons have been decadent for a long time.