Depends on the dungeon. AST has an instant stun, but WHM has a constant stun for at least 2 gcds before they become immune for a time. Assize is also instant 300 potency on all targets within range, and that is something no other healer has. This is extremely beneficial in dungeons when low HP adds swarm in, which is common in dungeons. You can argue Miasma 2 and Earthly star all day, but WHM will rid of them faster each and every time. Especially if you add a SC+holy in there on top of assize.
AST and SCH overall DPS might be higher, but I am curious about their burst damage, which seems to be strongly in favor of WHM. And overall DMG don't mean dick when the fights aren't long enough to make them an argument. And we're talking dungeons here.
