As a general Rule, in Square Enix's Game: "Final Fantasy XI", anythgin that can alterate the function of Time will give you the most noticeable increase in efficiency.
X% haste = X% more damage & X% closer to Weapon skilling.
Y% Double Attack = (Y x 2) = X% haste
I.E. If you have 5%-8% double attack added to party members, it functions as 5-8 aditional hits per 100 hits, or 5%-8% Melee Haste, with the added bonus of Processing on a Weaponskill (5%-8% chance).
Hunter's roll: if you had 5%-8% Accuracy on the top of your melee, and you were already at 80% accuracy, you would only get a 5%-8% increase in damage max per 100 hits.
Rogue's Roll: if you had an additional 5%-8% chance at doing 50%-100% more damage a swing you's be adding 2.5%-16% more damage per 100 Hits, with the added 5%-8% chance of critting a weapon skill.
Combining Fighter's Roll & Rogue's Roll:
Per 100 swings @ 80% Accuracy: you get 85-88 swings (+DA on WS)
thats:
9% - 22% increase in damage, when you include Rogue's Roll. (+DA & Crit on WS)
Hunter's Roll & Chaos Roll:
Per 100 swings @80% Accuracy: you get 84-86 more swings
Thats:
9% - 14% increase in damage, when you factor in Chaos roll.
Now keeping in mind the percents I was giving are grossly understated, you can see the merit in having Fighter's/Rogue's.
MATH R TEH FUNZ0RZ!!!
In the settup proposed:
Samurai Roll / Hunter's Roll:
84-86 % Accuracy @ 8 - 18 Store TP
you still would have benefitted more from Fighter's over Hunters:
85 - 88 hits @ 80% accuracy @ 8 - 18 Store TP.
War, War, Thf, Cor, Brd, Whm:
Fighter's/Rogues & March/Minuet for Melee, Healers/Evoker's & Ballad/Ballad for WHM is about as good a pt settup as you can get.
10% Base DA + 8-18% more, and an added 8-18% Crit rate on top of that...