Exar Kun & DE Sidious vs. Ragnos & Sadow

I doubt it anyway. And it seems as if the sith were more interested with sith magic and alchemy, I doubt that they were good duelists.

really, because Kreia stated that her generation were like children playing with toys compared to the ancient masters, dealing with dueling/sith knowledge.

Actually she was talking about Tulak Hord, who used a lightsaber and seemed to be much more of a dueler anyway. And how really would Kreia know just how great the sith were at dueling?

because she's a historian? Same way she knew everything about Ragnos, Pall, Hord, Sadow, Kressh, etc..

The thing is, she would actually have to see them in action to determine their dueling ability.

Why? She had no problem verbally fellating Ragnos, why would she have to see things for herself? She also saw the fall of the republic in her mind, what's your point?

The thing is, she actually was able to study sith magic (such as the teachings on Malachor V and Korriban, and holocrons etc.) and likely knew of their conquests, such as Sadow making a star go nova. Through these ways, she would be able to get an accurate indication of their power. However with dueling ability, the only way she would know is threw their conquests, and seeing as she can't compare their era to her's in regards to dueling ability, it means jack.

It would kind of be like researching into the past, and finding out that Mr. X was able to defeat Mr. Y and Mr. Z in a sword battle. You would still have no idea how skilled Mr. X was, because you would have no clue as to how skilled Mr. Y or Mr. Z were. Makes sense?