Honestly, the question never really made much sense to me.

Joseph is a hero. He helped out, and gave his life to protect his comrades whom he owed a debt to.

What his comrades did or didn't do, or whether his family knows he's a hero or not, has absolutely no bearing on whether or not he was a hero. Both lines are technically true. Yeah, heroes are also human, and he died. But he was still a hero, even if people don't sing his story.

You're arguing that Joseph isn't a hero because of the actions of the rebels. That makes no sense.