I've sunk my last 2 composites with a single bow hit (not purposely, I missed a shot because the ship changed speed without properly notifying me, the nerve of that guy
) and out of ornriness and an unwillingness to use torpedoes I waited in both instances to see what happened. Both sank in about an hour.
Sometimes ships don't go down. It was part of the real war too. But you do have a lot of mods, not all of which I've had time to experiment with. Some can be totally eliminated as suspects, like skins and campaign layers. I'd upgrade ROW to the latest version 2. Having Missing Hollywood Zones Effect on top of NSM 3.3 might be the wrong order. If you update ROW that won't be a factor.
If you're like me right now you left port with all the latest and greatest and now there's not a mod in your arsenal that hasn't been updated.