WHM doesn't have access to any usable DPS abilities in endgame now that healer gear doesn't have accuracy since all 3 DoTs have initial potencies, unless I'm mistaken as to how those abilities work.

SCH and AST both get access to 2 DoTs that ignore Accuracy (Bio and Bio II for SCH, Combust and Combust II for AST).

Bio and Combust have the same potency and duration, but Combust II has 10 more potency than Bio II. So AST's Combust II will deal 100 more potency in damage over the duration than SCH's Bio II since they both have a 30 second duration (~10 ticks).