15 STP from /sam
33 STP in TP gear
32 STP in WS gear
48 STP in TP is 19.2 per hit
49 STP in WS is 19.3 per hit
Total missing TP for a 5-hit: 3.9
Achievable when hitting 3/3 of the additional hits, fails when hitting 2/3 of the additional hits. 3/3 should be expected 85.7% of the time with capped accuracy. 2/3 should occur another 13.5% of the time (total coverage: 99.275% of the time you will land 2 or more of the additional hits).
Landing 2/3 hits is frequent enough that I would not consider that a reliable 5-hit build. With only 8% DA, you can't rely on that to make up for the missed base hit either.
Current, not necessarily optimal, gear set that I've been using on comparison:
TP:
Langdebeve +3 (fire)
Pole Grip
Protestas
Zelus Tiara
Ganesha
Brutal
Aesir
Lancer +2
Timarli
Rajas
Tyrant
Atheling
Goading
Calmecac
Lancer +2
WS:
Thew Bomblet
Varangian
Gorget
Brutal
Vulcan
Lancer +2
Lancer +2
Rajas
Pyrosoul
Atheling
Ele.Belt
Lancer +2
Wyrm +2
DPS w/6-hit build: 148.609
Rebuilding using your 5-hit config
TP:
Hagneia Stone
Zelus Tiara
Love
Brutal
Attila
Lancer +2
Timarli
Rajas
Tyrant
Atheling
Goading
Calmecac
Lancer +2
WS:
Hagneia Stone
Mekira-oto
Justiciar's
Brutal
Vulcan
Lancer +2
Ogier
Rajas
Pyrosoul
Atheling
Beir +1
Lancer +2
Gigantes
DPS w/pseudo 5-hit build: 135.014
6-hit build is 10% ahead of the 5-hit build using the same weapon. Further tweaks may change their relative positions, but I'm too tired right now to care.