What is odd about the list is that the first group is of people transporting goods. "donkey driver, a camel driver, a sailor, a potter, a wagonneer," so the potter stands out as strange. Given that resh and dalet often switch off, an easy explanation is that one is an error and duplication.
Similarly, in the Mishnah, we have a strange sound-alike reduplication for Sapan, the sailor, becoming a Sapar, barber, in approximately the same place in the list.
אבא גוריין איש צדיין אומר משום אבא גוריא, לא ילמד אדם את בנו, חמר, גמל, ספר, ספן, רועה, וחנווני, שאומנותן אומנות לסטים.
"both karar and kadar are mentioned, and it seems that karar is the more likely and the other should perhaps be crossed out."
I'm curious why you say that. Is there any reason why they shouldn't *both* be on the list?
It certainly is possible that both should be on the list. Neither are on the list in the parallel Mishnah. https://he.wikisource.org/wiki/%D7%9E%D7%A9%D7%A0%D7%94_%D7%A7%D7%99%D7%93%D7%95%D7%A9%D7%99%D7%9F_%D7%93_%D7%99%D7%93
What is odd about the list is that the first group is of people transporting goods. "donkey driver, a camel driver, a sailor, a potter, a wagonneer," so the potter stands out as strange. Given that resh and dalet often switch off, an easy explanation is that one is an error and duplication.
Similarly, in the Mishnah, we have a strange sound-alike reduplication for Sapan, the sailor, becoming a Sapar, barber, in approximately the same place in the list.
אבא גוריין איש צדיין אומר משום אבא גוריא, לא ילמד אדם את בנו, חמר, גמל, ספר, ספן, רועה, וחנווני, שאומנותן אומנות לסטים.
Something seems strange here.