In my Opinion Ahsoka needs at least Agility 5 and FR 5 to stand a fighting chance against Darth Vader, as seen in Star Wars :Rebels (2018). She needs also many skills from the Shien and Ataru Striker Tree. And I woul give her: Brawn 3, Agility 5, Intelligence 3, Cunning 4, Willpower 4, Presence 3. It is also possible that Morai improves her abilities, as the old Obi-Wan Version in Allies and Adversaries, which gives FR + 1 . Adversary 3 is a very good idea for her. So Vader has Adversary 4. By looking at Vader´s Strength Morai should grant Ahsoka at least 2 Force. And the Technique "Disruptive Strike" from the "Shien-Expert Tree" could help her to stand her own against Vader. She should not be as powerful as Vader, but her abilities should enable her to withstand him.