I think it makes sense as "ch" in German coresponds with "k" in English (and other West Germanic languages) at the end of a syllable (it's the pattern I've read about, not just my observation):I prefer to think of Schach- in "Schachmann" as the equivalent of Shake- in "Shakespeare" (but I'm like 50-50 on whether that's what it is).
I think it makes sense as "ch" in German coresponds with "k" in English (and other West Germanic languages) at the end of a syllable (it's the pattern I've read about, not just my observation):
make --> machen
cook --> Koch
etc.