iain,
I think that all the officers in the French army at that time would have the cultural level to write this text on a sword. But not as many would have had the poetic mind to do it ! :-)
In France before the Revolution, aristocratic families were sending at least one of their sons into the army. After, it was difficult to avoid not being incorporated during the first Empire wars, when nearly half of the French male population died or was wounded fighting for Napoleon.
During the 19th cent, these military traditions went on, mostly at the time the French were building a colonial Empire. Fighting for France was largely seen as an honor, and many French intellectuals, authors, poets fought during the many wars we were involved in around the world or in Europe.
Rimbaud's father was a career officer in the French colonial army, Rimbaud himself joined the Dutch army in Indonesia for a short time. Then he lead an adventurous life in Africa, where I'm sure he had to be put in circumstances where he had to fight for his life.
It's certainly not the discipline of the army that attracted the more educated Frenchmen in the army but the adventure, a certain romantism and idealism, or simply the will to defend France when the country was endangered.
Here is a list of the french writers that died for France during the two last world wars only:
http://fr.wikipedia.org/wiki/Liste_d...pour_la_France
Best
Nicolas