As WHM, two Holy casts will take care of the fires if you have at least soldiery gear. I've got 30 Alexandrites from maps and my WHM have no problem soloing all of them with iLv 110 gear. Some take longer because I keep having to duck their AOE attacks but none of them posed any danger of failing. This is unsubstantiated opinion, but I think WHM is thte easiest job for soloing maps.
Back on topic, I'd love having at least the Alex maps stack as well. It's not like the maps were supposed to be done by full parties or even light parties. So what if a player decides to stack 75 maps and do them in one day? It's not like we can just buy them for 200gil.