I dont use Sudema personally but one thing that can be said for her in regards to her value, her power is virtually the same as Braxas' acid breath except she can only hit one unit at a time and SHE ISN'T RESTRICTED TO SMALL AND MEDIUM UNITS.
This means that if she does survive and you can get her close enough, she has the potential to destroy a large or even a huge hero like Nifilium or Jotun in one D20 role that has much better odds of working than Dead Eye Dan's Sharpshooter ability.