If you're just talking about taking the players as they were: lifestyle, fitness etc and just dropping them into a team in 2017, I don't think any of them -even the very best- could make it at the highest level. George Best would be considered on the same level as an unfit, weaker version of Jack Grealish. Maybe not even that good. Best, Cruyff, Moore etc were little blokes with no power that could maybe give you 60 minutes at Championship level and they would most likely have limited impact. They'd be getting out ran, out muscled and just couldn't stand the pace or the physicality. That's my opinion.