The White Sox do not like using their entire international signing bonus pool. Therefore, their rosters are top-heavy without much depth. This year is more of the same, with a little difference at the top because Erick Hernández is not as heralded as, say, Norge Vera was last year, or Luis Robert way back when he started in the DSL.
One interesting note on the whole roster though: Nobody was born in the 90s, it is all 2000 or younger.
Hernández was a seven-figure signing, so he is getting big bucks from the White So to play.