@Nate
There have been 3 arguments presented against FDTs. The ludicrousness of the premise is one. The fact that it's widely available in this list but implied as rare in the AdMech is another. And the third is that it's unsatisfactory for the job (even if it made you immune to ordnance it would still not clear CAP to help your torps hit home). Add to that the fact that any IN fleet list will be able to pay 10-20 pts to give 1 or 2 of its Lunars or Gothics or Doms FDTs then it just becomes a terribly terribly awful addition to the game. Less is more. Drop this crappy rule, or limit it to only this crappy list. I really don't care which.
Oh, and by the way, your maths is off. Firstly, the cost of the NC option. When you said +20 pts over the 6 torps and +10 pts over the 9 torps you were right. However, that's as an option. It is well overpriced as an option, presumably to limit NC spam. However, when it's non-optional it's only worth at most, 10 pts more than 6 torps, or parity with 9 torps. So take 10 pts off for a start. Secondly, you started with a range-upgraded Tyrant as your base ship and then further upgraded the range off all 10 WBs, meaning your price of 260 included optional range upgrade (15 pts). So if you want to keep the range upgrade as +15 pts you'd need to drop the ship down to 245 for a start. Then drop it down by another 10 pts since you overvalued the NC. Then drop it down by another 5 pts because you started with an already overpriced ship. This brings us to 230 pts. Now drop it another 10 pts because of unwanted speed and the extra liability it presents to your fleet. And you get, hmm, what 220 pts? Isn't that what I said the unupgraded range Mercury should cost? I swear to god the only use for this ship would be to AAF into the heart of the enemy and blow up. A task for which torpedoes would be vastly preferable to the NC.
I wonder, are you afraid that it would be overpowered at that price? Really? A range upgraded one would be 235 pts, same as a matrix fitted Overlord. So you're getting less firepower from the Mercury at >15cm. You have to take a NC, when most people actually prefer torps (particularly for this ship!) and you're able to sit back and make full use of your range with the Overlord, without it outpacing the fleet and without fear that it's going to massively explode in your own lines. In short, even at 220 (235 upgraded) the Overlord is preferable, and I don't even like the Overlord (I'd take the Armageddon for sure). There is no way this hunk of junk is worth that much.
On to the Victory. The approximation of 1 lance to 3WB only works on 30cm weaponry. A strength 1 lance at 15cm is worth less than 3WB at 15cm. Similarly, 1 lance at 30cm is worth more than 3WB at 30cm if those WB can't get a LCS when firing at <15cm. So this approximation only really works as an average across the range bands presented. It breaks down when we extend the range further. So, when we make the Victory/Retribution comparison we should bear this in mind. It's also only worth noting this range favour to lances for the on-side weaponry; off-side weaponry will almost always be within 30cm. So focusable fire of Victory vs Retribution shows +1L to the Vic, +6WB to the Ret. Clearly in favour of the Ret, even taking the range discrepancy into account (1L=3WB<30cm, 1L=~5.5WB>30cm, so 1L@60cmLFR worth ~4-4.5WB@60cmLFR). Given that this ship now costs 10 pts less than a Ret and has the option to take a NC then it would seem to be fine.
Problem is, the Ret isn't any good. I don't see it getting the targeting matrix the Overlord got. With its weaponry getting better at closer range such that at <30cm it has +3WBe over the Victory it really is a line-breaker, for which role its range is fairly useless. The Victory on the other hand is a stand-off vessel for the same but opposite reason. In which case its range is useful, but its prow weaponry and armour aren't so useful, and its speed is also a little wasted (it could go down to 15cm like the Emp/Ober/Apoc/Vanq and still fulfill its role). So the Retribution is more efficient than the Victory, even though its conflicted design has been much lamented. Consider a Ret with 18WB@45cm for 355 pts. This is what the community would like and what we all agree is balanced. OK, so you don't want to change the Ret for various reasons. However, since you're introducing the Victory here then surely this is the benchmark it ought to be balanced against, and not the current crappy Ret.
This has mostly been an exercise in comparative ship valuation rather than any true gripe. At 335 pts (torps) the Victory isn't too bad. It's 35 pts more than a Desolator, but has the extra armour on the prow. This roughly ballpark for this upgrade normally, but it does lose the speed as well, which isn't too big a deal on a stand-off vessel, but with the 6+ prow that speed would have actually been useful. Of course, the Desolator is definitely the better ship. There isn't much between the speed/prow armour in terms of actual (ie, role) value, so the Vic is a little pricey still.
It compares unfavourably in stand-off role to a known good ship (Desolator) and compares unfavourably in a line-breaker role to an acknowledged bench mark (fixed Ret). Still, you could argue the Ret isn't fixed and the fleet can't get the Desolator. So I would just suggest upping the dorsal weapons to 9.
The Vanquisher is still just too pricey. I like the idea, but it really is not equipped to do what needs to be done. Unlike the Victory it could really maximise the prow torps and extra speed. It wants to break the line and in this role the range on the WBs is wasted. This makes it a terribly inefficient ship. It doesn't matter that it's inefficient, but at least cost it appropriately. Most of the time it won't be able to turn and the enemy will be able to dictate terms of engagement. It also has the same firepower as the Armageddon at <45cm, and slightly worse at >45cm (better off-side firepower, but less ability to manoeuvre to be able to use it). So take an Armageddon, add 4 hits, 2 shields and 2 turrets (no firepower) and then knock of 5cm speed and make it BB status (large base, crap turn radius). Let's just assume 10 pts per hit and turret and 15 pts per shield. That's a total of 325 pts. Now knock off the speed and give it BB status. Together I would call that at least 25 pts. If I had the choice between a 300 pt 15cm BB line-breaker or the same ship with 20cm movement and cruiser turn rate for 325 pts I'd take the latter. So 300 pts is probably a little high still, particularly when compared to the Desolator, but it's a nice round number.