I was reading a book entitled "The World at Arms" (The Reader's Digest Illustrated History of World War II)
A general remark:
Books like this one are the printed equivalent to History Channel shows. They can make a fine reading, but due to the very broad approach covered on few pages, aimed at the general public and the way they are written and edited (being more compilations and rewrites than result of original research), they are prone to have many oversimplifications, plain errors in detail, especially when it comes to technical details.
When you are doing research like HTC has to do for this game (at elast if you take things seriously), you will try get hold of as much primary sources as you can get (that's original documents: pilot manuals, manufacturers aircraft descriptions, official test reports, production statements etc.) Good monographs about your subject, adehering to scientific standards are the second best (and often invaluable) choice. Your book isn't any of it.
