As much as I love those two players individually, no I don't think so.
IMHO both Rondo and Smith are secondary superstars in the mould of Scottie Pippen. I don't feel either of those guys can cconsistently take over games offensively. Occasionally yes, consistently no.
I believe every contender needs a go-to guy offensively who you can turn to to carry the offense and hit huge shots in the clutch. As long as Pierce is on a basketball court we have that, which is why I still have some faith in us right now. Once Pierce goes we will need a dominant offensive player to take his place, and until we find one we will likely struggle to get past the first round.
On the surface the Rondo / Smith duo looks great - two talented, "do a bit of everything" guys with extreme physical gifts. On paper it would be hard to keep those guys together salary wise and still have the cash to get ourselves the offensive star AND role players we'd need to be a contender
Much as Id love Smith, he makes more sense on a team tho already has a go-to guy and needs a secondary star who can be q second or third scoring option whole doing a bit of everything. The Lakers (Kobe), Clippers (Paul), Knicks (Melo), Bucks (Ellis),Rockets (Harden), Bulls (Rose), Thunder (Durant) and current Celtics (Pierce), are all teams that Smith would be an outstanding fit on. For those teams he can improve them dramatically as a second or third tier scorer, a key rebounder, a defensive presence and a good playmaker in the frontcourt.