It seems like a lot of these problems could be partially solved by making a few simple changes:

- Adloquium/Eukrasian Diagnosis and Succor/Eukrasian Prognosis now no longer heal, only applies a shield.
- Indomitability can no longer crit.
- Pneuma is no longer affected by Zoe.

That would dial down the pure healing power of the designated shield healers, but it doesn't really matter because the fight design is still "mitigation is king".