[Suicide Junkie]

Well, in space you need a rocket engine to accelerate (or solar sail, whatever) So the torpedo looks a bit missiley.

The torpedo, would not be seeking a whole bunch, but instead be boosted to a really high velocity by its engine, with minimal course corrections. This should make it cheaper, smaller & faster firing than a CSM.

Since it has an antimatter warhead, it should be doing much more damage than a DUC, you may want to mod that if it is a problem.