If your bare shaft and fletched shafts are grouping together, a slight tail right probably doesn't mean much. I assume you're a RH shooter? If the tail right is more than 5* or so, let me know; in that case it may be above my pay grade, because a significant tail right should have your bare shaft impacting to the left of your fletched shafts.
A slight tail right could be caused by the target itself. It could be caused by your nocks fitting too tight on the string. It could be caused by a slight overstiffness of the shaft, but not enough to cause much of a separation between the POI of your bare shaft and fletched shafts.
If there is a slight overstiffness, it can sometimes be corrected by raising the brace height, if that is an option for you. Reduce the weight of your string silencers, or move them closer to the ends of the string. Move the centershot closer to center, if that is an option.
But since you have probably already experimented with increasing point weight and shaft length with no success, the cause is probably something other than shaft spine, like overly tight nocks. Correcting that may also correct the nock high, but I wouldn't worry about a slight nock high of 5* or less.