How does 1 photon torpedo Destroy General Chang's BoP in ST6, but 72 photon torpedoes blowing up INSIDE the Vengeance only "disable its weapons systems"?
Chang's BoP was hit by at least five torpedoes (the homing torpedo first and then several others when the Enterprise and Excelsior went all Django Unchained
on it) before it was completely destroyed, IIRC.
Plus, Chang's BoP is the size of a wart on the ass of the Vengeance, and is designed to be a stealthy lightly armored scout rather than a heavily armed and armored battleship.
Also, the torpedoes did significantly more than just damage the weapons systems. The ship was going down.