Another point that works in Johns favour (and this is not Lewis' fault, as he just happened to be born and played in the era he did) is that Johns competed against not just the best of the best, but also the fittest. Lewis was playing in an era when 90+% of players were semi-professional and had 2nd jobs outside of RL. Only the elite players like Sterlo earnt enough money to play RL full-time. As a consequence of this semi-professionalism, the players back then weren't as skillful and definitely weren't as fit as they are today. I was reading an article somewhere on the early history of the Newcastle Knights and I laughed when I read that during the 1988 pre-season training, their coach Alan McMahon made the players run 10km along some beach in Newcastle. That was considered "adequate training" back in those days. Oh, how much training techniques and methods have changed since then
When I watch highlights of matches from the '70s and '80s, I laugh when ppl say the players were more skillful back then. They weren't. It was very much "bash and barge" back in those days, and rarely did you see the scintillating plays that we've been accustomed to see this era from players like Benji Marshall, Billy Slater, Jarryd Hayne etc.
Johns has played in an era where 90+% are full-time professionals and train 5-6 days/week. As a result, the game is much more tougher and even if you are naturally talented, you will not get far if your fitness is not up to standard. That's not to say that Lewis is not a good player (I already made reference to his 1989 S.O.O. performance). Although Lewis was not the fittest player (I heard a rumour he used to smoke whilst on the sideline, dunno if that's true), I still think he would've done reasonably well if he was playing in today's game. However, most of the players from Lewis era would not last in the game today as they were well below fitness.