Yes, that's absolutely right. The point is that once your party is moderately well developed, the magical skills of the paladin and ranger are next to useless, with one possible exception. The monsters you are facing are too powerful for any spell-based attack at that level to be more than an irritant, and even the exception, Turn Undead, does no more than buy you a little time from one particular class of monster. And your own party is so powerful that the healing spells are a bit like sticking a plaster on an amputation.