You'd obviously hope that one of them would become a better 3 point shooter, but Rondo shoots well enough to become a devastating pick and roll guard- he's just never really played with anyone other than KG who can play it well enough.
The idea of a two point guard set up is to attack the rim relentlessly and break down perimeter defenses with ball movement.
Wade and Lebron have built a dynasty around this, and neither of them are the best shooters- they are just surrounded by excellent shooters.
I also liked the idea of Rondo and Marcus Smart as a twin PG combo, but Smart is much shorter than first thought. (Was supposedly 6 '4" and measured at 6'2" yesterday).
Smart and Exum could be nasty too if Danny wants to move Rondo on
