True, but that's because no one else has the same style. So she fills in that position every anime again.
But some of her roles are impressive, like Masane Amaha in Witchblade or Poison Sophie in Lupin III ova. Those aren't her stereotypical roles, but still performed greatly.
So i think her potential might be held back a little cuz of her unique voice, ironic no?

My absolute fav would probably be Yamaguchi Kappei, just because of the sheer of roles he voiced, one by one great roles. shamefully he hasn't been as active as of late. Yet even his roles are also all kinda alike. So when grading on variety of voices, i would choose Kuwatani Natsuko