hmm, that could work. granted, you'd need to get the warheads out of the ship since it's own armor might contain the blast, but something that can act as a layer of armor for most of the trip would make it easier for them to get though. still something we're likely not going to be able to do for a long time though, it's quite clearly innovation and the conservatives would raise a stink. hell, even some of the progressives might not like it, simply because inventing a harder to stop world killer is the kind of thing that can easily backfire.
I'm not sure we have to worry about our own armor plating..... they work on ripping a hole in reality and exposing the warp....it doesn't actually care what armor is in the way cas it bypasts matter entirely
its like worrying that the metal infront of a ship will stop the blast of a nuke.....yea, it will *technially* slow it down by about a billionth of a second (fun fact, nukes work just as well on sea-ships as they do citys....the US military tested this)
but yea. your other point about making *another* world-ender weapon is a bit of a question.
I think the main concern then is the possibility that this would just be so expensive that you might as well just make a normal ship and arm it with with the weapons.
----*screetch of the thought-trains wheels breaking suddenly*----
OH, and if duren doenst like the plot-implications of this.....no weapon can withstand the fury of the DM....(thats why nukes don't work in WH from what I recall)
--edit-- ...although I just realized that if the cyclonic torpedos work as I think they do (shoveing the nearest N kilometers of space partially into the warp) then its not a question of their power but rather their distence from the target and how much enemy material is in that N-space
.so a big thing for them is penetration...so actually.....
even if the torpedos on their own would be better then a ship for getting at least one off safely relative to their cost....the ship-eedo might still be worth it against space hulks as they could be made to ram the hulk with a long spike/hardened armor/space-ship-tier-power-armor to try to get as deep as possible before detonation....this is often a big concern for most explosive weapons but if the warhead doenst care about how tough something is but rather whats NEAR it...it becomes even more important and having a ship-sized mass at near relativistic speeds (which should be possable with enough prep time by pre-accerating) would probably be capable of piercing ...well....alot
I should point out also that a ship would be able to accelerate to MUCH higher speeds as well...no air resistence in space after-all so bulking up on engines and armor means that you have significantly more delta-v to use.
it also means that firing INFRONT of enemy ships become more important since their own velocity will carry them into what is basically a extended explosion radius.
sorry for the mini-essay...I guess I'm kinda excited I have SOMETHING to potentially add.
I might try to figure out other ideas to redo our military
(question...whats the radius on these torpedos? are they variable?)