Pros and Cons of each Healer Role

[Fricca]

Pros:
WHM: Cure III, Benediction, Assize, Most HoTs
AST: Cards, Disable, No cast Single-target Shield, Versatile
SCH: Fairy, Critlo, Deploy, Supervirus, Most DoTs, Most mobile, Versatile

Cons:
WHM: Not-so-versatile
AST: Least DoTs, Least Ohshit skills
SCH: Least HoTs

[VanilleFang]

Pros:
WHM: Cure III, Benediction, Assize, Most HoTs
AST: Cards, Disable, No cast Single-target Shield, Versatile
SCH: Fairy, Critlo, Deploy, Supervirus, Most DoTs, Most mobile, Versatile

Cons:
WHM: Not-so-versatile
AST: Least DoTs, Least Ohshit skills
SCH: Least HoTs

You forgot to include that WHM have the most AoE healing spells of the three (Assize, Asylum, Medica, Medica II, Cure III) as well as Stoneskin II. And buffs from cards can be seen as a positive as well as a negative because... You forgot to mention the RNG aspect of the Astro.

[Fricca]

You forgot to include that WHM have the most AoE healing spells of the three (Assize, Asylum, Medica, Medica II, Cure III) as well as Stoneskin II. And buffs from cards can be seen as a positive as well as a negative because... You forgot to mention the RNG aspect of the Astro.

I did say it has most HoTs, making it easier to party heal with it than a Diurnal Sect Astro. I've listed the relevant skills and said most HoTs instead of saying "Most AoE Heals" because usage of these skills can vary. I for one do not use my Assize to heal the party, i use it for Burst DPS. I dont see stoneskin II as much of a benefit cos it can only be used outside of combat but I guess that counts. I dont see how cards can be negative at any point. Its not something you should heavily rely on so having that something extra is always a plus for me regardless of RNG.

[Reinha]

I did say it has most HoTs, making it easier to party heal with it than a Diurnal Sect Astro. I've listed the relevant skills and said most HoTs instead of saying "Most AoE Heals" because usage of these skills can vary. I for one do not use myAssize to heal the party, i use it for Burst DPS. I dont see stoneskin II as much of a benefit cos it can only be used outside of combat but I guess that counts. I dont see how cards can be negative at any point. Its not something you should heavily rely on so having that something extra is always a plus for me regardless of RNG.

Don't WHM and AST have the same amount of HoTs? Am I remembering it wrong? WHM: Regen, Medica II and Asylum. AST: Aspected Benefic, Aspected Helios, Collective Unconscious.

For the thread topic:

I find the toolkits of WHM and Diurnal AST quite similar in power, healing-wise. Asylum vs Collective Unconscious, Assize vs Lightspeed + Celestial Opposition (AH/CU/LA), Essential Dignity vs Tetragrammaton, Synastry vs Divine Seal, Presence of Mind vs Time Dilation (buys you time to either dps or heal more). On top of these WHM has Benediction, Cure III and higher dps, and AST has cards and 2 DoTs that can't miss.

The lack of Benediction/Cure III equivalents makes AST a bit more challenging to heal with in tough situations. On the other hand the generous MP from Luminiferous Aether (3 ticks longer than Shroud of Saints without even being extended) and potential MP cards as well as the MP saved with cheaper AoE dps makes AST less challenging than WHM in long fights.