Honestly I also agree WHM feels the worst in dungeons simply because despite being a regen healer WHM has the least access to actual passive regens, AST gets 2, SGE and SCH get 3, WHM only gets 1 and its a bubble

It’s hard to overestimate just how much work kardia and eos do in dungeon runs so u always notice the lack of them on regen healers then I notice even more WHM’s lack of regens beyond that

I agree single target healing on AST is relatively dicey though till you get that second charge of essential dignity and celestial intersection because a lot of the mid range heals AST gets are AOE (star, CU and CO all in quick succession), WHM has the benefit of holy but a lot of tanks don’t really take advantage of it to better stagger their mitigation