I agree that trying to get everyone to use a given head might be of value to establish a baseline, but I actually think better "real world" data could be gathered by individuals shooting outdoors under a number of varying conditions.
You might find that shooting in a "windless" controlled environment of an indoor range that Vane B produces consistently tighter groups. However, once wind gets involved Vane A or C might provide drastically better stabilization and are more resistant to wind plane giving considerable tighter groups "under the conditions they will be used in real life".
Also, Vane A might provide better results with an expandable, while B does best with a 4 blade fixed etc.
The more data from various sources the less likely that you can use the information to support a "pre-determined" conclusion.
I worked as a statistician (actually a statistical analyst) for a number of years. My first question always was "what do you want the results to say" (before I even looked at the data) - because you can support a conclusion with data by selectively applying the results.
And for the guy who is shooting a mechanical head, outdoors, in 20F windy weather, the results of shooting indoors with no wind @ 72F with a fixed 3 blade may not be of any use OR give him false confidence in possibly the most "inferior" vane for his actual purpose.
Sorry, you got me thinking out loud here
![Laughing :lol:](./images/smilies/icon_lol.gif)