Heavy Torpedoes in Naval Command

I've played a couple of games of Naval Command now and in both the heavy torpedo has been decisive, almost to the point of unbalancing the game. This is even more evident with guided heavy torpedoes, which almost always hit and inflict +6 damage. If fired in a salvo, this damage can be overwhelming and tends to end up with a very big bang and not a lot left floating around afterwards.

So, for example, a guided torpedo must lock on to its target with a D10 roll greater than the target's Acoustic Signature (AS), which for a typical surface warship is around 5, adding the torpedoes accuracy rating, which for a heavy guided torpedo is +2. If the firing ship has an active sonar the torpedo also gets a bonus equal to the sonar rating, typically a +1 or +2. On a good day, it will only need a roll of 2 to succeed, assuming all the higher modifiers apply.

This is all fair enough and probably realistic for modern weapon systems like Spearfish or F21, but perhaps not so much for earlier first generation types. However, the real issue for me is the +6 damage that results from a torpedo hit, so I've decided to de-rate heavy torpedoes in my games to a +4, which is still twice the modifier of a light torpedo and equivalent to a lot of the ship killing missiles in the weapon tables.

I'll try it out in the next game that features heavy torpedoes to see if it makes a difference.