Yes, Moiraine has experience killing arrogant channelers who are more powerful than her. *NM* - Edit 1
Before modification by BlackAdder at 15/08/2010 05:26:29 PM
... they don't fight battles on paper. :p
Caddy is significantly more powerful than Moiraine, has much more experience, and has a wealth of ter'angreal which give her who knows what extra advantages. She's tough, and she's a fighter. RJ made it pretty clear that her reputation is well deserved.
Moiraine, on the other hand, seems to have that undefinable characteristic of heroes that lets them come out on top no matter how outmatched they are.
I'd say if the Moiraine of EOTW through TSR fought Caddy, she'd lose, but I suspect the post-Rhuidean Moiraine would present a far greater challenge. We can only speculate on what post-ToM Moiraine's situation will be, but assuming she hasn't lost her channeling ability or been in any other way altered, she's probably taken yet another level of badass.
But with no other parameters to judge with, I'm going to have to stick with the safe bet. Cadsuane wins.
Cadsuane is more powerful, much more powerful, but as stated this never seem to stop Moiraine who vanquished Forsaken who stood as high above Cadsuane as Cadsuane does above Moiraine. Also, all Moriane's conquests are very plausible. She's actually the most realistically believable hero in the story, far above Rand who can just do no wrong. He has taveren'ness on his side, she just has an indomitable will.
Also I suspect that balefire would overcome Cadsuane's ter'angreals.