Conclusion: It's too slow. With the disparity in speed and maneuverability, it would never land a hit with its primary or secondary weapons.
Assumes a favorable initial setup, which may not always be the case. Also you have to remember the Prometheus Frame's missiles are off-boresight capable. I can and have scored kills simply by launching them at random.
Science without context is no science at all. 
And science without evidence.
The Prometheus Frame is an existing ship, kicking ass in WoD.
The SF Kraken is nothing more than mere text and speculations. I wonder if someone would create a such a ship.
Nothing!? Im.....impossible. Those Seeker missiles are shock'n'awe.