So, I don't think you're wrong with your premise in that players can mature at different rates.
Skalski:
2016- 14 run defense snaps, two run stops (14.3%)
2017- 95 run defense snaps, 12 run stops (12.6%)
2018- 30 run defense snaps, 3 run stops (10%)
2019- 302 run defense snaps, 42 run stops...