Taking up Hal’s kind offer of subtitling my Tartakovsky episode, I realised that subtitling gives us the opportunity to change the context of the speech. So I’ve asked for the cat-being, who is now someone other than Ventress, to say:

[Count Dooku lands and exits his ship]
PREVIOUS LINE: Everything has been arranged precisely as you have requested, most illustrious Count Dooku
NEW LINE: The fallen Jedi apprentice seems likely to win your gauntlet, noble Count Dooku.
[Count Dooku: “Indeed”]
[She leads him in, they overlook the arena]
PREVIOUS LINE: I trust you will find what you seek.
NEW LINE: Watch her destroy these mighty warriors.
[We see fights, we focus on Dooku and the cat seated]
[//Removed shots of Dooku talking to Cat-Ventress//]
[Ventress lands in the arena]

That gives us a little context for Ventress, who is the main new takeaway of this prelude episode, so I think it’s useful. “Fallen Jedi” gives her acceptable backstory even if we’re sticklers for the rule of two, and an “apprentice” defeating these (presumed) top-tier combatants shows that even a Jedi padawan is formidable - helpful in justifying Ahsoka’s early seniority. Having Dooku agree (“Indeed”) that Ventress is likely to win also justifies him having two convenient lightsabers ready for her later, and ties in to the later angle that he respects Dathomiri ‘stock’.