There is no way that broadheads can fly identical to field points. The resistance on the blades will create a little more drag than a field point. I do think we can tune to where within practical hunting range they fly the same.
The heavier the arrow the easier it is for it to overcome the resistance the blades create, especially with small cutting area heads.
The only thing to debate is what is a practical group for field conditions. I can take a shooting machine and have it shoot the same arrow in the same hole at 60 yards. With a 1/2 dozen arrows it will produce a group the size of X. When broadheads are applied to those arrows and that group increases slightly to the size of X times .5 does that mean they still fly the same?? Statistically no, but for practical purposes?? Yes.
I have argued that I have broadheads that fly with fieldpoints, do I? Not precisely. Within reason? Yes, for hunting ranges.
I'd say don't knock
@RosinBag. He brings a lot of knowledge. I have disagreed with him on several things, but it's really on nitpicking things.
I'll agree that just because two arrows hit the same spot it's not nearly a large enough data set. Put a piece of paper up and shoot 10 field points followed by 10 broadheads, analyze that.
I broadhead tune at 60-70 yards. My broadheads hit with my fieldpoints at that range, they probably fly a little high at 20-30, but I can't see the difference. 1/2" ain't going to matter at 30 yards on an animal.