Comparing their first runs through Portland (age)
Yoan Moncada (21): 62 games, .277/.379/.531, 3.24 PA per K
Rafael Devers (20): 45 games, .297/.355/.564, 5.15 PA per K
Devers has posted far better K numbers throughout his career while facing the opposition at a younger age. It might not be indicative of much, but I wonder if he doesn't have the same hole in his swing/inability to hit breaking pitches. Regardless, impressive for a 20 year old!
Edit: To add some more comparisons...
Benintendi (21): 63 games, .295/.357/.515, 8.77 PA per K
Bogaerts (20): 56 games, .311/.407/.502, 4.92 PA per K
*Note - this ignores X's less impressive 20 game taste of AA in his age 19 season due to tiny sample size.
Betts (21): 54 games, .355/.443/.551, 12.65 PA per K