For a right handed archer, this should indicate that the spine of the arrows is too weak. In spite of the pattern, I suspect there is another problem. I have shot bareshaft tests for several years and I have never seen anything that looks like this. For a 15 yard distance, the variation is much bigger than I have seen. Also, it appears that the angle of impact is about the same for the fletched and bareshaft arrows. If the spine is too weak, I would expect to see a significant difference in the impact angle, with the bareshafts pointing to the right. The group size also indicates a problem. The bareshaft group is pretty good but for the fletched arrows there is a nasty horizontal spread and there also appears to be considerable variation in the angle of impact for the fletched arrows. I suspect you have a problem with the fletching not clearing the rest. With that degree of variation, I think you should be able to detect poor arrow flight. If you watch carefully or back up to a longer distance, I would bet you will see poor arrow flight and fishtailing for the fletched arrows. Perhaps it is just the photos, but that fletching looks huge and much bigger than you should need.