Yes, it´s rather Renaissance. But given the tech level displayed in the books, one of the essays of de Camp and the fact we are still talking about fantasy they would work. The Wikipedia entry has an interesting variation that was used in Iran in the 9th century btw.
Hm, one of the Conan comics I had (Sadly, turned to dust in the last thirty years) showed a lot of crucifications, like the Romans did. The whole scene resembled a lot the movie Spartacus (the one starring Kirk Douglas) including, as far as I remember, skeletons hanging there. But don´t ask me how this would work.
"In strange grammar this one writes" - Master Yoda