"They made a difference he does not"
He played 3 minutes in the first half and we were down 20. He played 16 minutes in the second half, and we won it by 8. Correlation isn't causality, but they're pretty clearly related.
Also, rebound rate is far from ridiculous. It's a much more useful stat than raw rebounding numbers.
And finally: He doesn't have to be as good as Emeka or Hasheem, and if that's what you're hoping for you'll be disappointed. All he has to do is continue to make incremental improvement - as he clearly, undeniably has done.