> Does anyone know if it was another clone or just coincidence?

EDLIN was a clone of CP/M ED. Was CP/M ED influenced by Unix ed? I don't know, but I somewhat doubt it. Gary Kildall's primary background was in IBM mainframe and DEC minicomputer systems (in particular VM/CMS and TOPS-10), and so it seems to me more likely that CP/M ED was influenced by DEC or IBM line editors, than by Unix.

That said, Unix and IBM mainframe operating systems share some common heritage. Both were influenced by CTSS. So, it may be that any observed similarities between CP/M and Unix line editors could be due to that shared ancestry, rather than any direct influence of Unix on CP/M.