CHT is 12.5% faster than DFB
DFB has 0.4% crit and 4 ap less than cht.
DFB - (top end + low end) / 2 = 99.5 damage
CHT - (top end + low end) / 2 = 82 damage
Add the speed with SnD on (1000 seconds for scale):
DFB 99.5 - 1.38 sec (724.6 hits in 1000 seconds) = 72097,7 damage
CHT 82 - 1.23 sec (813.0 hits in 1000 seconds) = 66666,0 damage
Average instant poison damage per hit is 26 (did not account crit / resist).
813-724.6 = 88.4 more hits than dfb.
88.4 x 26 = 2298.4 > CHT does 2298.4 more poison damage over 1000 hits than DFB.
Let's remember that off hand deals 0.5 base x 0.5 modifier from talents = 0.75
DFB - 72097.7 x 0.75 = 54073.275
CHT - 66666 x 0.75 = 49999.5 -> add poison damage 49999.5 + 2298.4 = 52297.9
52297.9 / 54073.275 = 0.967... > 96.7%
100 % - 96.7% = 3.3%
DFB deals 3.3% more damage including poison damage. I didn't add blade flurry which would make the speed gap even smaller meaning DFB would do more than 3.3% damage compared. ALSO poisons are single target which would mean that when cleaving, DFB would do way more damage.
so 3.3%-5% more off hand damage OR 0.4% crit and 4 ap (boosts main hand + yellows).
Bonus with DFB = 130 hp
Thoughts? + feel free to add the missing factors if you got the info.