How about just making something more unique and useful out of what we have already?

I'm not sure how four 20% chance of free/half-cost combo spell procs ever satisfied any checklist for "unique job identity". At best WHM has its longer (but non-self-extendable) HoT, more frequent power CD, and an extra direct healing ability, but in effect that just leaves it as the "healer-est" of healers, rather than having anything of its own. Its elements are left as flavor text, and its only unique mechanics are the same RNG we tend to complain about in AST, but with greater setup frequently required.