I understand what you mean by controlling the offense and I am telling you you are wrong. Paul and Ray have to initiate the offense at times as well. You love examples here's one. Doc has substitutued Ray for Rondo in the play where garnett and Rondo or Ray are on one side of the court, Garnett on the baseline post Rondo or Ray up top. Either Ray or Rondo feed Garnett who then swts the pick on the run by of Ray or Rondo and then has the option of feeding the open Rondo or Ray for a lay-in, posts his man up because he's now in an iso or passesout for a swing of the perimeter to the open Rondo or Ray who ran around a second big man pick and is open for the jumper.
That play was primarily designed to get KG a low post iso, a lay in from the cutter or an open jay on the other side of the court for the cutter. Most of last year it was Rondo feeding KG. Many times KG handed off to Rondo but Rondo wouldn't lay it in, couldn't lay it in or passed back out for a reset. If Rondo gets that ball he has to finish. So after seeing it not work this year and especially lately it is Ray running that play. Why? Rondo's ineffectiveness and indecisiveness in finishing and, if the play is run right, his inability to hit or take the jumper on the other side after a ball swing.
That same play is run with Pierce being the feeder/cutter/weakside shooter. It is very successful with him running it because he creates so much contact and is great coming off the weak side picjk for the shot. Same with Ray.
Now that is just one play. But that whole sequence needs to be initiated by the feeder and having the versatility of having multiple players being able to initiate makes the offense much more effective overall and harder to defend against.
See that's one logic you keep ignoring. That having multiple players being able to initiate offense is more difficult to guard against. It makes the team less predictable. It makes it more dangerous and effective. You see the best thing about the Big Three is their mulitple assets on the offensive end. They all shoot, finish and pass well above average for the average player at their positions. Using all of those assets in different areas and at different times is the most important aspect of the Celtics offense.
Having Rondo calling the plays and initiate them limits this team and effectiveness. It really is that easy. Now as long as Rondo is playing intelligently and staying within himself when the offense isn't being initiated by him, he can still be a valuable asset on the offense.
As for the timing as to when Rondo's play picked up last year and when it did this year, I feel you are a victim of overthinking the situation. In every single sport when a star goes down, other players pick up their game and compensates. It has been happening in all sports for decades. It is the same thing with Rondo's timing. He mentally concentrated more and honed his game because he knew he had to.
The explanation is really that simple and has nothing to do with sweeping changes in the way Doc has his team run. I mean think about what you are saying. Coaches are creatures of habit and system. Over a short term they will NEVER change their system for better efficacy they will just change players. The same thing happened here. Rondo simply played smarter, played better, and concentrated more when the team leader was down because he knew he had to.
Prove is in the pudding. During the 10 games KG hasn't played in due to the injury and suspension, Rondo averaged 7.1 rebounds per game. Over the rest of his career he has averaged 4 RPG. Why? Because knowing that Garnett, a great rebounder isn't there Rondo made the concerted effort to rebound more because he had to for the team to succeed. Under your logic, Doc giving Rondo the reins on offense made Rondo nearly double the rebounder during those game? Of Corse not. Rondo concentrated more and improved his game to compensate. It's been happening in sports since time began.