Still reading this book, but I just came across this passage:
'Furthermore, crucifixion typically ended with the guards breaking the legs of the crucified to make it easier to remove their dead bodies from the cross.'
This was not the reason the legs were broken. When a person hung on the cross, his body would sag, and he would have to push himself up with his feet in order to breathe. Therefore, if the guards wanted the person to die quicker, they would break the legs to prevent him from being able to breathe.
John 19:31 The Jews therefore, because it was the preparation, that the bodies should not remain upon the cross on the sabbath day, (for that sabbath day was an high day,) besought Pilate that their legs might be broken, and that they might be taken away. 32 Then came the soldiers, and brake the legs of the first, and of the other which was crucified with him. 33 But when they came to Jesus, and saw that he was dead already, they brake not his legs: