And, the Rockets supporting cast was THAT bad. Luther Head was our third/fourth option in 2007, and stunk it up in the playoffs. In G3 or 4 of that series, we only had four players score in the ENTIRE game. In G7, McGrady scored or assisted/indirectly on every Rockets possession except four. Chuck Hayes, Rafter Alston and Shane Battier were our other three starters, two of whom can't dribble or create at all. The other, you don't WANT to dribble or create. The only play JVG seemingly had in his play-book was a McGrady screen and roll with the center, where the defense would come with help, in which McGrady would either go around to a.) free himself for the jumpshot, or b.) find the open man in the corner. This is why the Rockets barely missed a beat without Yao, the offense was run almost the same with/without him, and Mutombo was just as good defensively, so we rarely missed a beat. Though, I will agree that Rockets despite this should have still advanced - their only season I'd consider to be an underachieving year (without considering injuries as underachieving); because in '05, and '08 (without Yao), we just didn't have a team that could beat those Jazz/Mavericks teams. McGrady wasn't particularly efficient in that series shooting the ball, and Yao was extremely turnover prone, and exposed defensively by Boozer.
In '05, we were pretty good offensively after the trades, and it's worth noting that Sura and Wesley were hobbled by the time the playoffs rolled around, Juwan was out for the season, so we relied on an aging/injured backcourt, and PF's in the mold of Ryan Bowen, Scott Padgett or Clearance Weatherspoon. Then consider '05 Yao was seemingly always in foul trouble, and very inconsistent with his play, I'm still not sure it's fair to expect these Rockets teams to be among the best offensively.
A Jeff Van Gundy coached team has never finished better than 19th in ORTG (and that was almost an outlier) -- they finished 15th in McGrady's two best seasons w/ Houston. And Orlando being in the Top 10 in ORTG in 01-02 and 02-03 is pretty impressive considering the crap of a supporting cast he had.
So, when you consider that Adelman's offense was finally implemented these past couple of seasons, and the fact that Martin, Scola, and Lowry are pretty good offensive players, I'm frankly not too surprised to see us finish top 5 in ORTG, and similarly not surprised to see us finish below average defensively.
Pierce on the other hand has shown at the very least that he can play on an absolutely spectacular team if you put talent around him, and thus he has shown more than TMac on that front.
Isn't that a kind of funny statement? That we give props to Pierce b/c he can play with an absolutely spectacular team? I don't know if McGrady fits as well as Pierce on those Celtics teams because of what everyone alludes to in efficiency (and that's a legitimate argument against him), but Allen would still do his thing off the ball with McGrady, Garnett's effectiveness would not have reduced, and guys like Perkins, Posey, and the shooters would be able to do what they did. Perhaps Rondo might not be as effective, but he wasn't ridiculously that good in '08 anyways.
And I don't know if I buy the different view on the narrative of McGrady carrying those teams without Yao. Those Rocket teams were considerably better w/ McGrady in the lineup, Yao or not. And that served vice versa, with Yao and without McGrady. I definitely wouldn't call it "the team didn't really get better or worse without TMac as long as they had Yao." And definitely not TOO much worse without either of them. Look at '06, an even less efficient hobbled McGrady by his standards were 27-20 w/him in the lineup, and 7-28 w/out him. Similarly, I'm not sure why the lack of drop off when Yao went out of the lineup hurts McGrady's case, in fact, that should help it, IMO.
Overall, I agree that Pierce has his advantages in efficiency, and longevity, however, I'm not completely sold there is much more to that argument (and that might be enough an argument since they're not too far off in their peak).