Using european illustrations as a guide to middle east practices is dicey. Jesus was likely not blonde or blue-eyed, as in many Vatican paintings.
As to the Romans, they used X type crosses to punish thiefs, and if you research a little harder you will find that Jesus was dilberately punished in the style of the thief. His wrist and ankles were likely pegged to the wood with Iron nails, because they were efficient, easily made, and reuseable. All of these things were used by the Romans to prolong the life of the punished and to make sure they suffered, and thieves were particularly ill recieved by Roman authorities.
Jesus was brought up on charges of sedition, punished as a political mal-content, and made to suffer the double indignity of being punished with the common thieves.
The authorities didn't take kindly to the locals talking about replacing them with a new form of government.