How often have we heard, "Million dollar arm and 10-cent head." I think the pitchers that are just nasty competitors, doing whatever it takes to win (or as I like to say, NOT lose), are the toughest to face. Some, like Clemens, have the great stuff, but look at Maddux. Certainly not overpowering, but smart, and as nasty of a competitor on the mound as I have seen.
I think the college scouts get caught up so much in the tools, that many kids maybe less raw talent, but with great mental make-up get left out in the cold. To get further off-track, I bet the coaches that have a sense about recruiting "make-up," are much more successful than those that just look for tools--and end up with "tools".