Shiv

I was grinding leather today (in my usual lazy fashion - BS > SnD > spam SS) when I wondered something: maybe Shiv is more effective in a front-on spam fight than SS?

Now the caveats here would be:
- combat dagger spec (I'm 15/41/5)
- dagger in MH (I have Ced's Carver)
- fast weapon in OH (I have Revenger)

SS is definitely going to beat Shiv if Combat Swords spec due to the reduced energy cost of SS and the likelihood of having a high-damage sword in the MH. However, comparing SS to Shiv with the above caveats:

- SS: 129 wpn dam + 113.5 SS dam + (170 instant poison VII dam * 20% chance to apply) = 276.5 average damage per SS
- Shiv: 107.5 wpn dam + (170 instant poison VII dam * 100% chance to apply) = 277.5 average damage per Shiv

Now of course that isn't so impressive a difference, but remembering that SS costs 45 energy (combat daggers remember) and Shiv only 35...

For a 10 second grind fight (100 energy at start plus 100 regained during fight):
SS: 276.5 dam * 4.44 cycles = 1229 total dam or 122.9 DPS
Shiv: 277.5 dam * 5.71 cycles = 1586 total dam or 158.6 DPS

So it seems that Shiv is about 29% more effective in a front-on combat daggers lazy grind fight.

Now this wasn't just to show off my dubious math skills, I have a question: what have I missed?
- I am assuming that the % chance to hit with the SS and Shiv is the same; is this correct?
- Given that Shiv is an OH attack, which usually has only 75% damage (with maxed Dual Wield Spec, as Combat Daggers should have), should I apply this?
- Any other stupid and wrong assumptions?

With the 0.75 weapon damage applied to the Shiv calculation (assuming it still gets the full damage from the poison), Shiv still comes out on top with 143 DPS vs 123 DPS.

You may say "so what, this is only applicable in very limited circumstances" and you'd be right, but hey the servers are down so why not think about this stuff? :)