From what I've read, the Manziel family has a history of drama. I think it was great of Charlie to offer his advice. Perhaps he has learned from his past mistakes. I trust we all have. I'm no stone thrower.
If Charlie Sheen has cleaned up his act and can be a mentor to help him, then that is good for both of them. I remember Mel Gibson lending a hand in the same way to Britney Spears, and she is doing great now.