My first attempt at multi dotting went badly :P I think I matched my single target however i soon changed some stuff.
single target 42-44k
2 targets 46-48k
3 targets 55k
Above that with four I could not make it a dps increase
Eclipsed dot hits for about 67k
Starsurge hits for around 63k
Normal dot hits for about 53-54k
Unlimted targets stay in eclipse and spam dots with lunar shower about 40k
Effectively I have ignored times of old and I put dots down almost to 100% gain procs of starsurge and i rank starsurge above everything else the amount of procs I was getting at point allowed me to almost move a complete eclipse with only starsurge really need a way to tell if you are missing out on the damage procs like missing a hot streak type thing.
If you make sure to use as many starsurges as possible it makes it worth multi dotting since the dots no longer do the core of the damage.
As for aoe it could be one of many things:
Single target = normal
Two Targets = multi dot but hope you get lots of procs
Three targets = multi dot procs should really carry you in and out of eclipses quickly
four targets = Not sure cannot find a way to beat 3 currently
Five-eight = Using only the eclipsed dot and starsurge spam (won't give you much over 3 -4 targets as you only gain the difference of non-eclipsed to eclipsed dot)
Eight - ten = Say hurricane does 6k then you would need 10 targets to match your 3-4 target dps
< CA (67*2) *15 seconds about 2 million or 134k each global
In order for hurricane to beat that you would need about 20-24 targets with hurricane
All numbers were mostly taken from unbuffed dummies this will scale better but then so will all the spells, the extra crit in a fully buffed though will really help out 3-4 target dotting. Also this is very much guessing, nothing has been actually tested but hopefully it will give you an idea.
For deathwing will hurricane proc spellweave or am I going to be a very sad chicken ?
Also I don't rate soul I think armoured chicken will out do everything especially since haste is high but devalued because of all the starsurge procs over 50 million on 3 targets I nearly matched starsurge hits to wrath and starfire together.