Just another topic where the WT has taken a different stance, for no other reason than to set them apart from 'Christendom'.
The evidence indicates that crucifixion was not the same for everyone. There were various styles- some punishments involved a simple stake, others used a cross beam. Some people were hung upside down, others in different ways for amusement. Some used ropes and not nails, Sometimes there was a seat- or horn that protruded into the persons private areas, to make the ordeal more excruciating.
There is evidence in a crucified skeleton from around the time of Jesus that had the nails driven into the sides of the ankles and therefore, no footrest was used.
In summary, there were various methods of crucifixion and and no one can say for certain which crucifixion method was used on Jesus and it doesnt really matter. Even the gospels are not eyewitness accounts.