I'm trying to complete the Pendulum quest, I'm at the part where I need to destroy the pirate's military forces.

The issue is, when I disable their ships, my fleet stop firing and doesn't destroy them, so fighting them is taking forever (3 years now and I haven't even destroyed 10 ships)
If I am fast enough, I can destroy the small ones, but even the smallest Big ship si way too tough, even with the Anubis.