Steve, if you wish to verify the author’s credentials or experience I suggest you contact wild sheep, or why not ask at their forum? Most of the writers appear to be dedicated hunters. www.wildsheep.org. Target shooters and tactical community mostly discuss moa click’s, Atrag’s and lots of other technical details etc.

Why do you think they screw up in first place, poor knowledge of the animals anatomy, or not able to visualise properly?

Cheers
Johan