Maata #22, started at 19, never developed past a 3rd pair guy.
Pouliot #8 played 34 games at 21, 22 games at 22, 11 games at 23, didn't start until he was traded to Vancouver at 24 and was a JAG by 26.
Sundqvist played 18 games at 21, 10 games at 22, didn't start until he was traded to St Louis at 23.
Guentzel played 3 years in college, an 11 games AHL cameo, started the next season in the AHL, 33g 21-21 42, a tad bit more impressive than Frost in the AHL at 22.
Sheary, 4 years college, then 1 1/2 AHL seasons before coming up at 23 years old
Rust, 4 years college, then 1 AHL season, 11 game NHL cameo, started next season in the AHL before coming up at 23 years old.
It was the highly drafted players who were rushed, and who also failed.
The later picks who went to college were well marinated and didn't get to start until they were 22-23 years old.