There is a little difference, stiffness of the shaft is measured by spine but the oscillation of th larger diameter shaft are more quickly stabilized than the skinnier shaft. really the difference is very small and not enough for most of us to ever know. I will take the lessened wind drift and deeper penetration of the skinny shafts over perhaps or perhaps not a very small accuracy improvement.

most I know that shoot the fatter arrows such as the fatboy arrows are looking for hat arrow touching a scoring ring instead of being very close