Nah, decapitation can absolutely be done in a single strike. It just takes the right angle and swing. Like someone else said, there’s been footage of it made. It doesn’t even take anything fancy; I saw a video of a machete doing it back in the wilder days of the internet.

Anne Boleyn was decapitated in one stroke by a sword according to eyewitnesses.

Given how beheading videos used to be internet bread and butter, I’m sure most people over the age of 30 know exactly how much effort it takes.

guillotine enters the chat

I watched a documentary about Samurai swords. They are used to be rated by how many bodies they can cut through with one motion so a beheading is no issue.