So I am posting here again to use a reference link for Bgwiki. I saw the fTP values for spinning slash and ground strike needed verification and I love Great Sword so I wanted to confirm them.
tldr: fTP values in Bgwiki for Gstrike and Spinning Slash are accurate and the verification comment will be removed.
I did testing on Ogre Fly in li-telor. See stats for def/VIT on Bgwiki. First test was on 99DRK/NIN with spinning slash at 1k, 2k, 3k tp with a 30base damage GS, 213 STR, 175 INT, 832 attack. fSTR works out to 11 and WSC to 116. (+0.5 physical damage limit for DRK, no WSDB or gorgets or anything like that).
Calculated damage at 1K TP using 2.5 f TP.
1 Hit : Floor(Floor(Floor((Wpn+fSTR+WSC)*fTP1sthit)*pDIF)*Randomizer)
min=(Floor(Floor((30+11+116)*2.5)*4.25) = 1666
max=Floor(Floor(Floor((30+11+116)*2.5)*4.25)*1.05) = 1749
avg(divide by 2): 1708
Actual values of 18 weaponskills at 1k TP:
min:1672
max:1748
avg: 1709
This is aligned with 2.5fTP calculations.
Repeat same gear for 2k TP using 5 f TP.
min:3336
max:3502
avg: 3419
This is aligned with 5fTP calculations.
Repeat same gear for 3k TP using 7.5 f TP.
min:5019
max:5269
avg: 5144
This is aligned with 7.5 f TP calculations.
2nd test was on 99DRK/NIN with the same setup for ground strike.
Calculated damage at 1K TP using 1.5 f TP.
min=(Floor(Floor((30+11+194)*1.5)*4.25) = 1496
max=Floor(Floor(Floor((30+11+194)*1.5)*4.25)*1.05) = 1570
avg(divide by 2): 1533
Actual values of 23 WeaponSkills at 1k TP:
min: 1502
max: 1570
avg: 1533
This is aligned with 1.5fTP calculations.
Repeat same gear for 2k TP using 3 f TP.
min: 3000
max:3137
avg: 3065
This is aligned with 3fTP calculations.
Repeat same gear for 3k TP using 5 f TP.
min: 4994
max: 5229
avg: 5116
This is aligned with 5 f TP calculations.