I've started a Perception/Agility playthrough -- Perception because I never did marksman rifle/penetrator perk on my first perception build -- and though I haven't played my first horde night yet, I have to add my voice to the people who have complained about this here before:
Knives make zombies rage way more often than clubs, baseball bats, sledgehammers, spears or the stun baton. Now, granted, I start with a power attack when using knives, and I don't with spears. With clubs and bats and sledgehammers, a power attack often drops zombies to the ground, so I wouldn't even know if they raged. With knives, you get to fist range with the zombie, you do a very slow attack, and the zombie rages. It got to the point it catches me by surprise when they don't.
Even normal attacks seem to rage them more often, but I've stopped doing those because they are too ineffective. They are good once you got some bleeding going, but only if the zombie did not rage, except zombies will rage too often and catch you at too close a range.
The knife isn't as bad as it looked to me at first, except for the raging. It is really at a major disadvantage when it comes to rage compared to other weapons, whatever may be the reason. Say what you want about what the chances of raging are with knives, it's just not what I'm seeing.
That said, I'm playing at Insane difficulty. If difficulty increases chance of raging, then that would account for it. And, to be clear, it's not raging because I have to keep hitting them over and over at this difficulty, it's rage on first hit.
