It's stretching the suspension of disbelief rule a bit much. He and Luthor knew each other as kids? Really? The pre-Crisis version made a little bit of sense. He was Superboy's enemy in Smallville and when he moved to Metropolis, Luthor just followed him to keep trying to kill him. SO it makes no sense because it really is just random coincidence. Which is one of many reasons why I don't like it.