He also only averaged 24 minutes. APG is not a poor indicator. Guys who get hockey assists tend to get official assists as well. Dwight is at best a mediocre passer and playmaker. for a center.
Harden's Greatest strength is getting buckets! Can he be a playmaker for some stretches of a playoff game? Yes. See the OKC playoff portion of his resume when Westbrook played pg the bulk of the minutes and Harden got to be a playmaker in spots. He was deadly until finals when the moment got to big for him. He has not shown that he can be the lead playmaker, lead decision maker, lead scorer, and defend consistently in a playoff or regular season game for that matter. He is not there yet. I'm going by his on court history, not what I think. Harden starting along side a guard like Rondo would make the game easier for him and Dwight. Also, please stop saying Dwight is a playmaker. He wants to be and he is working at it, but that is not a strength in his game. That is why they need playmaking PG to give them balance and put them in positions to be there best on both ends of the floor. They can not do it by themselves as much as they and you think they can.