A general must be an expert in many things. He/she must have excellent knowledge in the fields of logistics, psychology, strategy, diplomacy, politics and bureaucracy. Not to mention the art of war and how to actually spell bureaucracy. Many of the most well-known people in all of history were generals, and being one requires immense knowledge and skill. As a result, these chaps need quite a bit of schooling if they are to perform all the tasks expected of them. There are simply so many things they need to know, and a very limited time to learn them. So why is it so essential for them to deploy precious time reading up on chemistry as well? The answer is, quite simply, to study the element of surprise.
Again, I am so terribly sorry.