In my opinion, i feel Raskta is a powerful duelist as she was implied to be the greatest duelist of her era and showcased her prowess against Bane. That said she was being amped and her force defenses were also being amplified. I am assuming that Raskta is unamped, in which case i'd say Ventress's force powers along with her talent with the blade, would earn her the win - with difficulty of course. Other wise. an amped Raskta would take the win with some difficulty.
Nice match up Joker.
Honestly, the way I read that is that, in that scenario, her Force defences were relatively weak (so Farfalla's were stronger, and her's alone weren't strong enough to defend against Bane). That she would be super easy to take out with the Force (Asajj is hardly a titan) isn't really consistent with her reputation as this mass Sith killer, unless you assumed she always had a Jedi with her providing her with additional Force defences. Typically people that fast in combat also aren't weak with the Force, and it doesn't make much sense that she'd completely neglect her Force defence.