If Jordan and Magic played in today's game, they would have put massive effort in shooting threes as they grew into the game like today's players. I have no doubt that Magic and Jordan would be much, much better at that shot than they were.
I think the only way to predict different eras, is to project the possibilities of one era with the advanced training benefits the other has/had that weren't available before. On the other hand when you come fight down to it it's impossible to do...