It's really not "closer than people want to admit".
Knies has potential, but that is still under the assumption he REACHES that potential. I also think Brady has room to develop and grow too.
Knies best season is 29 goals and 58 points in a full season. Tkachuk has a 35 goal, 83 point season (2 years ago), and a 37 goal, 74 point season (last year).
-> So right off the bat, Tkachuk has shown he can play at a completeley different level offensively than Knies can - THAT, is not even close.
Look at the playoffs this year, Knies with 3 points in 6 games, compared to Brady who had 7 points. Once again - not even close.
Knies was the FIFTH best forward on his team this year, Tkachuk is regularly the 1st or 2nd best forward on his team.
44/58 (76%) of Knies points this year were also assisted by, or scored by Matthews and/or Marner. Both of whom are both significantly better than anyone that Brady gets to play with. It's not even close. And that's before considering points that Nylander or Tavares factored in on as well.