Well since these torpedoes could be 'fresh' from the line so to speak, they probably have better durability too, so they can withstand some attacks, but not by much. So they'll last more than one hit, making these torpedoes a worthwhile investment. After all, torpedoes have three factors to contend with:
Velocity
CD's
CM's
Those are three countermeasures, the target merely has to try and evade.
If these torpedoes got a health buff, then it would help to alleviate one countermeasure to a point. There are far more counters to these weapons than pro's, I think its time to change that.