Seriously as a footballer Isak is miles more talented than Shearer. It isn't even close. That being said the same gap exist when we talk about the ability to be a traditional number 9.
I don't think so but the style they play does rely on extreme counter pressing and using the ball in a way whereby they can recover some energy.
When the press is off as it is today it looks rank. The players just dont have the legs for it they are way off.