Very interesting HANS !
I am no expert on the German Language, I do speak arabic and russian and english as a primary language but German was never in the cards for me.
From numerous printed accounts and various verbal accounts with historians, I've always seen or heard the words KOBES or KOBIS or such associated with Jacobs name and then they elaborate that it’s a short for “Jacobs” but also "arrowhead" or "pumpkin" and such then they claim these where patronymics for him, and the reason his Albatross aircraft has an arrowhead badge painted on it.
I have no hard evidence if any of this is accurate though, other forum member could elaborate as they have translated much of his personal diaries and letters for Cross and Cockade or Over the Front periodicals. Possibly my misspelling of the word is so “way off” that it confuses the issue? Or another more likely senario: I'm the one confused by the issue
I am interested in your thoughts on the subject.