Now you’re talking past me, and provoking me, and I don’t like that. Are you talking about 5th or fifteenth century? How does this relate to the comparing of piece A to piece B? If one is fake then how come the other one shows the exact same detail IMPLICITLY (the stitches on the Sudarium). What were the stitches for? It’s unclear because the answer to the question is on piece B the shroud which shows that the stitches were used to hold together this person’s long hair after he died.
You’re asking the why question of why did this person have long hair. My problem to say it so crudely again was to compare piece A to piece B to see if they fit together, but since you asked me the why question let me ask you back: why not? Was there anything preventing Jesus from having long hair? Your confusion seems to come from thinking that he had sidelocks which implies that this was his usual hairwear i.e. the jewish stereotype. How would you look after having beaten for twelve hours straight? Your hair would be all over the place, which is what we see. Why the hair was arranged the way we see it postmortem on the shroud? Good question. Maybe the parts of his hair that were loose enough to have fallen forward were drenched in blood so badly that there was no point in trying to put all of the hair back together into a ponytail, which for all we know could be a purely postmortem feature meaning that the person may’ve never even had his hair in a ponytail ever during his life.