I don't think you watched him pitch. He is not a strikeout pitcher. He threw 83% changeups. He was a beast for 14 innings against MLB hitters. I don't care about his age. As long as he is cheap he gets a shot.
There is nothing linear about a Top 100 Prospects ranking. The difference between ranking 90th and 91st on the Baseball America Top 100 Prospects list is often infinitesimal, as the gap between No. 1 and No. 20 on the list is always larger than the gap between No. 75 and No. 125.