So DW + Vorpal is better than Fencer + Savage?
Yes. TP speed is a thing.
https://www.bg-wiki.com/bg/Vorpal_Blade
1.375 x 4 hits for main + 1 hit for off.
200/1024 = 0.1953125 Brings us to 1.5703125 per hit against 5 hits. WAR should be averaging at least +1 DA per WS (low end), so 6 total hits.
1.5703125 x 6 = 9.421875 fTP
Now SE said they were raising Vorpal's crit hit rate at 2K and above, same thing with Evis. Going to use that data (10/25/50) for basic idea since we never got Vorpal's base info and it seems to fit observed data.
Master WAR's base Crit rate is 20%
WS + Moonshade is 13.75
Back is +10
Hands are +8
Ring is +5
Ammo is +2
58.75% Crit rate, 98.75 under Blood Rage. This is me estimating it a bit since I can't be sure what Vorpal's Base crit rate is, I put it at 10% because that seemed to fit the data but it could be 5~15%.
That means half of those 6 hits are going to crit on average and nearly all of them with BR up.
Master WAR's Critical Hit Damage is 18% with another 6% from Yetshila +1 making it 24%.
At capped attack 4.35625/3.33125 = 1.3076 * 1.24 = 1.6214 or 62.14% more damage for crits vs non-crits.
Then we get into weapons,
Tanmogayi +1 / Reikiko adds another 4% Crit Rate and 5% Crit Damage so those numbers go up.
And 60% STR make a solid WSC bonus.
All this puts Vorpal at a very high damage for /NIN thought not as has as Savage as Fencer, with the difference being more then made up through the TP speed of DWing.