You guys are stuffty commanders. No sane officer would ever willingly just plain sacrifice a ship with hundreds of people on it. It would be one thing if this was a naval battle, since you could pick up the survivors, but there are no lifeboats in space.
Bomber squadrons: Start attacking the bottom leviathan's weapons. If that fails, see what happens when you hit the eye.
Fighters: Fly cover for the bombers.
Player ship: Fire all available weapons on the top cruiser
Prosecutor: Boost shields and make preparations to evacuate the crew of the other cruiser if needed. Also, fire on the bottom leviathan.
Other cruiser: Boost shields, prepare to evacuate if necessary, and fire on the top leviathan.