The fact of Simmons shooting fouls at 56% alone makes him a liability in 4th quarters in playoffs.And at some point that will be the difference if these two clubs fight it out for years .Foul shots in Boston in that atmosphere Simmons will fold.Brad will game plan around his weaknesses for a decade.Marcus with his quick hands will disrupt his trips to the paint and semi will take charges along with Morris.The Celts can run an array of different style defenders at him never letting him get comfortable.  They will have one thing in common strength,desire to play defense and can't be bullied.
Now Jason seems unruffled at the line and Jasons all around game in playoffs becomes more valuable.Many strengths and negligible weaknesses rather than a guy playing point guard that has no jump shot,no threes  and shoots foul shots that poorly.
How many series over all these years came down to foul shooting-who you targeted,who you wanted to handle the ball.How you defend the last shot.Call him what you want but against the Celtics he is going to struggle