I'll wait for evidence that supports your assertion
What I "asserted" there was a preference. Not sure what would constitute "evidence" for that.
If you want evidence that being cut is painful, it should be easy enough to perform a quick home test. But probably avoid cutting your neck or any arteries.
Also having felt the shock of an electric current,
The stunners used in slaughter of cows are typically not electrical devices. They use pressurized air or a chemical explosion to propel a metal pin against the skull. If it goes well, the resulting concussion results in near-immediate unconsciousness. Having been knocked unconscious a few times in my life, I can attest that the pain associated with such only occurs much later, once you regain consciousness (and often not for a little while after that).
But as to electric stunners (which are used for pigs): being myself an electrical engineer, and so having been electrocuted many times, I can again attest that the pain only occurs after the shock is over with and normal nerve function can resume. Although I've never been shocked to the point of unconsiousness, I don't see how one would feel any pain in such a process until regaining consciousness. I've certainly never felt any pain during an actual shock (immediately afterwards, sure, but not during).
Point is that stunning methods only present the possibility of pain or trauma if something goes wrong (they aren't correctly applied, or the animal is not then killed before regaining consciousness). Killing by throat-slitting guarantees pain and suffering (including the awareness of helplessness in the face of imminent death) even when everything goes exactly right. This probably was the most human way to slaughter an animal before modern times - sure beats stabbing them to death, or bashing their brains in with a rock, or poisoning them. But there's a wider array of options available now.
[note that the ability of the method to render the animal insensate is directly proportional to the impact on the skull]
Right. So?
what we really have here are innovations of the old hammer on the skull method used to knock out animals before technology took a hand.
Right. So?
Stating that impact especially on the skull, never mind more than once, is less stressful [remember that the animals are in line watching the ones ahead get whacked] than bleeding out is a remarkably obtuse argument to me.
The stunning set-ups are typically constructed in such a way that none of the animals can directly see what's happening (including the one being stunned). For that matter, there isn't much to see - the stunner is placed against the animal's skull, there's a "bang" as the pin releases and retracts, and the animal goes limp. We aren't talking about some caveman crushing their skulls with a sledgehammer or something like that.
Likewise, I don't see why watching one's fellow animals be tied up and have their throats slit open would be any less traumatic than watching the stunning process.
More than that, I don't see why you're on this mission to prove that modern slaughter methods are less humane than Halal or Kosher methods in the first place. Just to spite some activists in Britain or wherever that want to ban Halal butchery to piss of Muslims? If so, you should be aware that Halal and Kosher slaughter are both legal, recognized methods in the entirety of the West. The relevant laws in the US explicitly classify them as acceptably humane, right alongside stunning-based methods. The mainstream is totally okay with this stuff, and kosher and halal meats are widely available (I had halal meat for lunch yesterday). For that matter, there's no shortage of Muslims who are fine with including stunning into halal butchery, so it again seems like you're going out of your way to manufacture an argument here.
And in the process missing the real issues with humaneness in animal slaughter, which have nothin to do with variations between methods (all of the ones under consideration are widely considered acceptable, if done correctly) and everything to do with failures to properly implement the methods as they are supposed to work. It's not an issue of which particular methods are used, but of what institutional and systemic frameworks are empowered to ensure that the methods are implemented correctly.