Jordan still holds the record for most Offensive Win Shares in a regular season with 15.2 back in 87-88.
Harden is certainly near the top of the list in terms of a guy who combines a very high usage rate with very high scoring efficiency.
He generates more three pointers, for himself or teammates, than anybody else in NBA history.
I'd also wager he's got the record for three pointers made + free throws made in a season. Last year he had over 600 free throws made and over 250 three pointers made.
That doesn't make him the greatest offensive player of all time by any means. But he is unique in the annals of NBA history in the character of his offensive production.
Personally I find Harden impressive but unappealing. He treats basketball like a parlour game, not an expression of teamwork or creativity. He's found the statistical seams of the sport and is trying his best to break it.
A game in which both teams do nothing but attempt threes (many unassisted), dunks, or free throws might be a great exhibition of offensive efficiency, but it would not be fun to watch.