Gibraltar dont do it !!

[Fifi]

So you need to deactivate Collateral damage (and all dependencies) as well as Zone (box) AP damage when zone (box) damaged...in shcollisions patch.

Then in data/script/AI/init.aix you can fine tune the non merchants behavior (hence destroyers)
I have only changed hydrophone difficulty min to 0.50 and max to 0.70
And sonar difficulty min to 0.50 and max to 0.80
Keep the rest unchanged...

Best is to create a Jsgme mod with the correct path like above, for this init.aix so you keep unchanged original TWOS...and put it in your TWOS parts folder.
Or save the original TWOS init.aix somewhere for later backup if needed.

You can test it with single mission TDW FX update test, or any other single mission where you have destroyers chasing you.
If my settings seems too easy or to hard to you, you can change them of course to your liking ...

Have fun