Id rank them
1. Detmers- points leagues SP has the most value depending on how they are set up. Detmers has the highest floor value wise in a points league between the 4 players imo. Similar stuff and savant page to Manning, but as a lefty it plays much better long term
2. Thomas- highest chance of becoming an impact player
3. O'Neill- best tools, a good season and then a step back this year. Could rebound
4. Manning- as a RHP the stuff doesn't look good long term
In a non points league...Definitely Thomas over the rest