Aloha Shipmate,
Firstly thank you for your service!
So the key thing here is this is an ARCADE style game not a simulation, so in most cases you need to throw realism out the window. When we say we try to follow SOME historical and realistic nuances that, in some cases, means we try to follow those things in terms of content, not always mechanics.
That being said, being a historical ARCADE game, balance is required.
Also the IJN Shimakaze DID have 3x5 610mm Long Lance torpedo launchers who's torps would travel 40,000 meters or roughly 21.5 nautical miles, so being able to drop 15 torpedo over the horizon (or not being visible) WAS a thing.
Remember what you might find fun, some others may not. If we were to limit the torps that DDs carry we would also be limiting the ammo that other ships would carry.
Mahalo,
-Hapa