The current "hero" category covers characters who are potential ring members, but also have attached story events and unique portraits. (A la Kallyr and Theya from King of Dragon Pass).
So, Beren, Ayvtu, and Yatakan, obviously.
It also includes the Former Wheel and Redalda, who have unique portraits and story roles, but don't quite fit otherwise--the Former Wheel has a random name and random (usually relatively weak) stats, and isn't considered a hero in-story, even though the debug file calls her hero4. Redalda doesn't give you advice, but she's
And it doesn't include (currently) Lyafor or the Wheel hero who is mentioned several times but never appears. (Autronos, I think.)
I'm not sure if this is a good way to make the distinction or not--"hero" means a few different things in the game, Maybe the category should be called something else to avoid confusion. Any thoughts?