RE: Explain this to me?
Follow the tuning advice in the photo above and do so incrementally. Make only small adjustments and I bet you'll be able to watch your 3 blade broadhead arrows "walk" toward the field tips.
Keep in mind, changing your rest will obviously change your site pins. Don't worry about the pins at first. Concentrate on the relationship between your bh's and field tips. Once they're hitting the same spot based on your rest/nocking point adjustments, then readjust your sights.