If you need a large group of people to do something correctly, you need to document how to do it and train them on how to do it. The Army can't just assume that every pigeon handler comes from a background with pigeons, will just "figure it out," or that within recruits / draftees, there will be enough people who are interested in pigeons that it will "just work."

Nor can the Army assume that the pigeon expert, who wrote that book, will be available to handhold every pigeon handler with their pigeons.

This, BTW, is an important lesson for scaling a successful business. Properly documenting processes and training employees is critical.

Finally, this extensive attention to detail is why the US Army is one of the best armies in the world.