This is just more a curiosity than anything else, but I find it weird that there are many shafts that have a butt diameter greater (some significantly so) than 0.600, when the largest grip diameter for non-putters seems to be 0.600.

For example, I’d like to try the NVS hybrid shaft, but its butt diameter is 0.625, so if I put a GP Tour Velvet 360 (with a core of 0.600) on it, my grip is now almost a midsize if I understand it correctly.

What is the thinking or reason for having such large butt diameters?  Reduce wrist impact on the swing?  Something else.

Thank you.