Ok, if the Knights were under control of the Librarian('s imprint, I guess) and she was trying to help John stop the Didact, then why did said Knights still treat the Chief as an enemy? Wouldn't it have made more sense if Forerunner had several of the Prometheans helping the Chief fight a large mass of Covenant to at least get him to her? I know the purpose of Forerunner was to clear a signal and tell Infinity to stay back, but that's a question that's been confusing me lately.

Or if not helping John, at least remaining docile--neutral in the conflict or just walking around doing Promethean stuff, not paying attention to him or the Covenant, just minding their own business.

When the Didact regained control of the Knights, the only thing that changed was the color. And that's why this doesn't make sense to me.