Yup, this is correct.

Only ninja with the taitou symbol near their name will be immune to debuffs and get that 20% increase

Sasuke's only purpose, for me at least, is to do is buff and increase damage even further in the first few rounds that you're immune.

If you're looking for other taitou ninja that would work well, try using Kimmimaro, who's a good tank, or Orochimaru, who has pretty awesome overall stats.

Hidan or Kisame are also sword- bearing ninja. As is Suigetsu.

If you're going to use Root of Warrior, I'd suggest getting Jugo, as he'd buff and and provide a shield for Kimmimaro and Sasuke (and any other cursed mark characters)