“Should point out that decapitation is not necessarily more brutal or painful than being shot to death or a host of other possible execution methods”
what?
Muslim decapitation isn’t one full swipe and they’re done....they “saw” through the neck with a rather short knife.
A single blow decapitation with a sharp blade is about as instantaneous a death as can be imagined. If there is any pain, it could not last more than a second or two. There are good arguments for the guillotine being one of the most humane methods of execution.
OTOH, being gut-shot and left to die without treatment means several days of agony.
Of course, one can always cut a head off with a dull pocketknife, I guess, which seems to be a specialty of the Islamists.