Tachi: Gekko
From FFXIclopedia, the free Final Fantasy XI encyclopedia
* Modifiers: STR:75%
* Damage Multipliers by TP:
100%TP 200%TP 300%TP
1.5625 1.875 2.50
Justice Torque 5 STR (7 attack 6.3 acc fairly negligible)
Snow Gorget Increases fTP multiplier by +0.1 and adds some amount of accuracy to all hits of the Weapon Skill.
Calculating Justices increase to WS damage +5 STR will give you 1-2 fSTR. 1 fSTR 75% of the time 2 fSTR 25% of the time.
Assumming Hagun 75 damge weapon which is rank 8 max fSTR of 16 (8 +8).
When STR-VIT value is high, fSTR can be approximated by ((your STR - monster VIT)+4)/4
so lets say you got 43 more str than your target your fSTR would be 11. (43 + 4 = 47/4 = 11.75)
Making haguns base damage 75+ 11= 86.
Add in the 5 STR from Justice it will become 75+13 = 88.
88/86 = +2.32% increase from fSTR best case secanrio, but only 1.16% increase when you get 1 fSTR from the Torque.
{2.32% x .25%} + {1.16% x .75%} =
.58% + .87% = 1.45% increase on average from fSTR
Now Calculate the WSC 75% STR for simplicity lets say 100 STR.
100 x 75% = 75
Add the 5 STR
105 x 75% = 78.75
78.75/75 = 5% increase.
5% + 1.45% = 6.45% increase from Justice Torque on average.
5% + 1.16% = 6.16% increase from Justice Torque when getting 1 fSTR.
5% + 2.32% = 7.32% increase from justice when getting 2 fSTR in best case scenario.
vs Snow Gorget
using gekko with hagun at 100% tp gves you an fTP of 1.875 + .1 from the gorget.
1.975 + 1.875 = 5.33% increase.
Conclusion given the str and fSTR values I plugged in assumming Hagun gekko at 100% tp Justice will always win. And if you happen to be getting 2 fSTR from the Justice the Snow Gorget gets stomped.
I feel like my math must be wrong somewhere but if it is I donno where I went wrong.