There is a difference between a role player and a primary/secondary ballhandler not getting FTs. Klay doesn't handle the ball like... at all... he's got one of the fewest dribble per shot ratios in the history of the league from a perimeter player. He is not relied to break down the defense, he's not relied to drive, create advantage, etc. He's a finisher(of the possessions). Probably the best there has ever been in his role. He's like a... extremely souped up rich man's version of a Korver/Danny Green/JJ Redick types. There just aren't many opportunities for him to get fouled. When you are a PG and you have the ball in your hands in most possessions, not getting fouled means one of two things - you are either not aggressive enough, or you cannot create advantage situations where you put the opponent in compromised positions.
In a vacuum not getting fouled is not a problem if you are efficient enough. The problem is that Klay not getting fouled doesn't effect his efficiency which is extremely high(again he gets easier off-ball shots), while a primary/secondary ballhandler not getting fouls effects his efficiency partly because by the nature of his role he gets harder shots and he needs to supplement his efficiency through drawing fouls in order to prop it up.
Also... pure number of FTs isn't really a great stat(since it doesn't take into account how involved you are in the offense - the more involved you are the easier it is to get fouled). You should be looking at free throw rate(FTr), it's more indicative. Russell's FTr this year is .111... Rubio's is .277, which is about 2.5 times higher. And again you will not get much argument from me about Rubio's efficiency... he's always been inefficient offensive player. Which BTW is the case with Russell too... right now he's at 51% TS%... which is bad.
