From what I've read of scouting reports... they had about the same scale of stuff that Hendricks does at his age. Yes, they were both in the majors at his age... but they were also taken out of high school. Hendricks was taken out of Dartmouth, and is in his 2nd season in the minors. As I said, though, I'm not really trying to compare him to those guys. That's just the general level of his type of pitching. You could also point to Derek Lowe, Wandy Rodriguez, Tim Hudson, Mark Buerhle, etc.
However, to simply rule him out because he doesn't throw 95 is a bit silly. There have been nearly as many guys to succeed at the MLB level with sub 92 MPH stuff as there have been to succeed with 96+ MPH stuff. I think a guy that can actually pitch... rather than just throw... has a better shot at turning into something worthwhile. While I would prefer a guy who could throw good heat and do so with strong command and control with an assortment of secondary pitches, I'm not going to simply crap on a guy that can do so without the high velocity.
However, I will concede that you could be right that he's an advanced level pitcher dominating guys at the lower levels... and could flop once he reaches a level where the batters are just as advanced as he is.