6 jobs can proc anything in Abyssea.

MNK WAR NIN WHM BLU BLM/BRD. You don't need a bard main to trigger weakness. TH makes 7. Nothing on this Earth could warrant bringing a SAM or a DRK to Abyssea, Slashing Blue or no Slashing Blue.

With that said, it's just Abyssea. It's not like BRD SAM RDM couldn't trio ... everything in the entire game bar-AV/PW at 75 either. Who cares?