Fangraphs ranks all the minor league players based on performance (this year only), age, and level. I don't know how accurate they are, but FWIW here are where they rank the Guardians prospects out of 3,906 total.
Top 1%: Robert Arias, Travis Bazzana
Top 1-2%: Cooper Ingle
Top 2-5%: Tolentino, Tugboat, Harrison Bodendorf, Ralphy, Miquel Flores, Chourio, Kody Huff, Juneiker Caceres, Halpin, Genao, Aaron Walton.
Top 5-10%: Khalil Watson, Franklin Gomez, Anthony Martinez, Nolan Jones, Stuart Fairchild, Luis de la Cruz, Jackson Humphries, Bennett Thompson, Khal Stephen
Just missed the top 10%: Justin Campbell, Dean Curley, Logan Allen, Nick Mitchell
Nine of the names listed above are at AAA. Tugboat, Ralphy, and Genao are at AA but could be moving up based on being in the top 5% of all minor leaguers.
I'm surprised Halpin is ranked this high as he's only hitting .250/.713 as a 24-year-old in AAA.