Definitely my opinion would be that Son and Rumba are two different claves
I would also consider 6/8 clave a third one ... I can see how that could be debated though. Also isn't there a Brazilian or Bossa clave?
Are you familiar with "The Clave Matrix", by David Penalosa? He was [maybe still is] a member. I have it but haven't gotten into it yet ... too intimidating
If you like deep clave theory discussions go through David's past posts ... heavy and often over my head, but like I said deep thoughts when it comes to clave.