How about you first define what you think of as an 'elite offense' is. When we all agree upon the definition, then we can apply the test to see if Rondo has ever met that threshold.
A team that regularly scores above 100 points, that wins games via offense instead of relying on defense to create a substantial portion of the offense; a team that is in the top 5, or at least the top 10, in offensive efficiency; a team that consistently generates good looks, and only rarely suffers from extended scoring droughts.
Some of those teams in the Big 3 era were quite good in terms of effective field goal percentage, and overall scoring efficiency, that's definitely true.
But first of all, Rondo wasn't really the "leader" of the offense in '08. Even in the latter part of 2009, I seem to recall Paul Pierce as primary guy. Rondo obviously had a great post-season run in 2009, and his role on the team took off from there.
Second of all, none of those Big 3 teams was ever truly overwhelming offensively. There were certainly stretches -- early on in the 2009 and 2011 seasons stand out in my memory. But offensive stagnation, especially down the stretch, was a hallmark of the Big 3 era. When the team was at its best in 2008 and 2010, scoring runs were fueled in large part by forcing turnovers on defense.
What I'm trying to say here is that I feel that Rondo has to prove that he's such a valuable offensive player by actually leading a prolific, deadly offense. There's a lot of bowing at the altar of the pure passing point guard around here, but personally I feel a major factor in judging the job that a point guard is doing as the initiator and facilitator of the offense should be the overall performance of the offense.
Passing for passing's sake and assists for assists sake are not worth much. We saw that at the start of last season. If it seems that I'm suggesting having a point guard who passes better than he scores is necessarily worse than the opposite, I need to recant. That's not what I'm trying to say.
However I disagree strongly with the converse assertion. In fact, if you look at the leaders in assists for this past season, and then look at how their teams performed offensively, there isn't a strong correlation between having a point guard who accrues assists and having a difficult to defend team.
I look at the teams at the top of the list of Offensive Efficiency this season, and what do I see? LAC, Miami, Dallas, Houston, Portland, San Antonio, OKC. All of those teams have something in common -- at least one primary ball-handler and playmaker who is either a deadly shooter, a significant scoring threat, or both.
Tony Parker and Damian Lillard, combined, averaged just over 10 assists this season. Yet I think it would be foolish to suggest that either of their respective teams would be better off with Rondo running the offense simply because he can average double digit assists, or that he's a better "pure passer."