This is right up there with 'No enemy CVs were sunk by level bombing'.
The math is simple.. calculate the trajectory of the shell/bomb.
If that trajectory intersects the trajectory of another vehicle ( air/ground/sea ) then calculate damage.
The thing folks are blatently ignoring is the thousands of hours of game play we have vs. the actual hours of practice enjoyed by the real combatants. A lot of the lessons we have learned over the years were also learned by many of the combatants, yet they didn't have the luxury of being able to live after the lesson was learned.
These thousands of hours of experience have been used to accurately calculate such aformentioned trajectories.
Given enough players, we could lay out a level bombing strategy where no fleet could possibly escape destruction, there are only so many angles/velocities that can be changed, and you can account for that.
So treat getting main'd by GVs like having to end your flight on a runway for successful landing. You know they can kill you.. don't give them that shot.