Ok, it's all speculation based on who these guys have played up to this point. It's gambling. But I'm not sure Knight is that much better than Nolan Smith - if at all. And Smith can be had in the late first round.
I'm not advocating even getting Smith. I'm making the point that the PG position is one you can fill much more easily than you can a talented big.
You are aware Nolan Smith is a senior, and was on a stacked Duke team (not that Kentucky was half bad either). Where as Knight is a Freshman (who I think skipped a grade somewhere in his life because he only turns 19 in December). Chances are Knight is going to do some major improving in the 5 year age difference there is between him and Smith.