In new spring I believe Cadsuane states that when Moiraine reached her full strenght she would be among the strongest women in the WT and possibly the strongest along with Siuan & Elaida after some old AS died from old age. It could well be that Cadsuane was counting herself in this group who were due to die as she was old even then.

Either way, unaided by angreal I think the strength difference between the two might be a bit like the strenght difference between the various forsaken, not enough to be certain of the outcome of a duel.

Cadsuane has the ter'angreal and a lot of experience in fighting if she took on all those male channelers but Moiraine is no slouch either. One on one with both prepared and face to face Cadsuane would probably win except for one thing. Balefire!

Moiriane showed that when it comes to taking on someone who as a big advantage over her i.e. Be'lal she simply makes the battle more even by using balefire which cannot be blocked. Cadsuane on the other hand would probably use it if she knew she had to but not until it was the last resort.

The way I see it going is Cadsuane things she is stronger with her angreal and ter'angreal and plans to shield and capture Moiraine. Moiriane for her part is aware of Cadsuane's reputation if not her exact capabilities so she is taking no chances. She uses balefire from the start and unless her aim is off or Caddy can jump out of the way she is nothing but a memory.

If Caddy did get out of the way however I suspect she would unleash hell and eliminate Moiraine using raw power from her Angreal.