Having worked in publishing for a number of years, I would urge you to be aware of the difference between the author and the publisher's marketing department.
The author *may* (and I emphasise it is only a 'may') have gone into it with honest impartial intentions keen on exploring the history of the longbow.
But then the marketing team got hold of it and decided they need to make it sound like a contentious and critical exploration with exposes, revelations, and critical new ideas and opinions. Just to make it marketable.
So they may, in some cases, give the book a title that catches the eye, or add a subtitle like the one presented here. Wrap it in a sensational cover.
The author will have had nothing to do with that and it may not be representative of the author's intentions.
Maybe.
But the old adage is definitely true - never judge a book by its cover.