Honestly, I see this as a non-issue.

PLD has Clemency and can cross class Bloodbath and Mercy Stroke.
BLM has Physic for low level content.
SMN only has access to Physic due to the shared base with SCH, which they've admitted was a mistake due to any changes to the base class abilities affecting both.
For RDM, we have no information on its kit, so even bringing it up is pointless.

Bringing up Solo PotD, that has only every been set as a challenge, not something the game should be balanced around.