The problem with your theory is that Harden is one of the most efficient scorers in the NBA when you look at him statistically across all categories.

I do agree though that having Lin pass to harden and run into the corner is silly. Not because it takes the ball out of lins hands necessarily - but because it then conversely puts Lin into a situation where he is most inefficient.

Watching rockets games I do think there's space for mchale to get them to share the ball more. There was one sticky point during our mid season losing streak and then again towards the end of the season where harden was forcing lots of shots and trying to drive and dry fouls and not getting calls. Jeremy can really help on nights like that.
I've said this before but I was surprised after watching jeremy in NY - how good of a passer/playmaker he was in Houston. He had better vision and court sense than I remember him showing in Ny and showed he wasn't as turnover prone as we thought him to be.

On the flip side it's Jeremy's responsibility to get better as a shooter so he can k mock down open looks he's presented with.