This book is full of useful info on army tactics that can be used in game such as tactics, strategy, communication style, efficiency etc. and in that segment it covers it great. However in real army you would get info on each weapon and vehicles used in battle, so additional pages covering pros and cons of every one of those I would consider mandatory in guide like this. But in intro saying author says he deliberately excluded those and focused on tactics only.
The other thing I would say it doesn't cover anything is campaign although it mentions it covers singleplayer game. As someone who doesn't play multiplayer, and in campaign there is no much command missions, this guide is not much of a help.
