Sure, they had guys that weren't "effective". It isn't surprising they weren't effective at closing.
You started off with the idea that a significant amount of effective set up men couldn't close. You appear to now be saying that poor relief pitchers can't close.
I specifically stated that he was age appropriate. But do you want "prospects" playing at the league age or do you want them young for their level? He also averaged over a strikeout a game at low A the year prior.
Yes, really.
He's been age appropriate for his level, which means old for a prospect and his K rate is a huge issue.
If you are 21, in A ball, you can't be striking out 125 times in 80 games.
Sisco and Mountcastle both made top 100 lists.
https://www.mlb.com/news/chance-sisco-named-on-top-100-prospects-list-c214551404
https://birdswatcher.com/2019/07/02/baltimore-orioles-where-orioles-prospects-rank-in-updated-baseball-america-top-100/