Meh. My humble opinion is that the 'problem' for guards like Rondo and Rubio is from being convinced or told to be something they are not. Whether it is coaches telling them to or themselves deciding to, to try to become 'shooters' is a mistake.
I firmly believe that it is NOT really and truly necessary for every PG to be a 'shooter' in order to win in the NBA anymore than every big man has to be a 3PT shooter. Those are misconceptions, imho.
I've followed the NBA very closely since the 70s, watching a lot of different trends and in my opinion the one constant is that players (and the teams they are on) succeed when they do those things that they are best at and fail when they try to do things they are not so good at.
It's a simple truth that even the lowliest NBA player could probably dominate the average non-NBA shmoe in pretty much every skill: shooting, dribbling, dunking, whatever. But in the NBA, if a player with less-than-average-for-the-NBA skill in something tries to use that skill, he's going to get whacked. That's why most 7 footers, despite having ball-handling skills that might put you and your buddies on at the Y gym to shame, should not dribble more than necessary on an NBA court. That's why a lot of guys who look like great 3PT shooters during workouts for draft scouting videos shouldn't take a single shot outside the arc in the NBA.
You aren't helping your team by trying to do something that you aren't above average at.
A good coach should try to put the players that he has in position to best leverage the talents that they have that are elite. Not try to pretend he has 5 identical players on the floor. You win basketball by winning match ups. The means matching your team's best skill at something against the other team's weakness.
Pass-first PGs like Rondo and Rubio should focus on what they do best and let the rest of the game take care of itself.