Right, Cortez had sheer dominance. If one were going to try to rationalize any of these three pitchers being ranked #3 on stats alone (because I'm pretty sure no one on this board has actually seen them pitch) he would be the one. Among 67 pitchers aged 16/17 in the DSL with at least 30 IP his 9.80 K/BB ranked 1st, his 0.99 BB/9 ranked 1st, his 2.64 FIP ranked 3rd, his 3.09 xFIP ranked 2nd.
Hernandez is ten months younger, sure, but his meaningful indicators weren't nearly as impressive - 7.81 K9 vs 9.66 K9, 2.31 BB9 vs 0.99 BB9 - that's why his FIP came in almost a full run higher at 3.58. Still encouraging no doubt, but only 12th among those 67 DSL pitchers aged 16/17 to throw at least 30 IP.
Comparing Prado to Misiorowski on raw stats is Apples to Filet Mignon. One put up his numbers in the DSL, the other in the Carolina, Midwest and Southern Leagues. This is multiple magnitudes of difference in competition level. Not to mention there exists video evidence of Misio being a mammoth human with ridiculous stuff. We literally know nothing about Prado (or any of these guys) besides what it says on a computer screen.
"I can't see/know exactly what", sums up our collective knowledge of these pitchers outside of their stat lines pretty well.