The crown of thorns was a unique “signature” invention to Christ’s crucifixion. You probably wouldn’t find other crucifixants wearing a Crown of Thorns. It was unique to Jesus because he was being crucified for calling himself a King. Researchers consider the Crown of Thorns a unique signature when they try to identify artifacts as relics potentially related to the crucifixion.
That said, whatever crown actually looked like - I honestly don’t think the Roman soldiers spent a whole lot of time working on it - either because they didn’t have time, didn’t want to get hurt, or simply didnt really care. And, since the Crown of Thorns was intended to make a mockery of Jesus, it was probably thrown together in some inane fashion and rather quickly (like in a matter of minutes) with the primary concern of making sure it would just stay together while they were torturing him.
The best scientific suggestion I have found for something like what the crown probably looked like:
The video suggests the material for the crown was probably a red flowered branch of a bush called “sarcopoterium spinosum”, which is a member of the rose family. I guess, if one was going to make a mockery of Jesus, the pretty red flowers (and they are pretty) would probably look very effeminate for any man of that day to be wearing, and they probably would have wanted the crown to possibly go in crazy directions to make him look sort of weak and clown-like while they scourged him. This would probably explain why the crown might have taken more the shape of a “cap” . It doesn’t necessarily mean it was, but, again, I am assuming it was poorly and quickly constructed, and it was aimed at making him look like a fool, so a well-constructed nosegay of thorns (like we see in the Notre Dame crown) probably wouldn’t stand out the same way as some half-hearted structure, flowery and flying in all directions (like the cap) might have appeared.
It’s also worth noting that the shape of a yamaka (sp?) is more like a cap, too… so, while it may be hard to justify such an argument, I think the shape of a king’s crown may have been more like a cap back then, or a wreathe of laurels…
$.02… Hoping this provides for some good food for thought and some positive contemplations…
God Bless and Happy Easter!
wm