It was said at the end of the 19th century that the majority of military texts were published in German.

Two texts (one -judged by the title- a report of someone who has been in America for seven months and the other apparently being a kind of CV summary) mean very little if anything.
It's difficult to estimate their influence (in part because many relevant historic archived burned down in '45 or were looted towards Moscow) among the thousands of publications of that time.