Castillo 9+ k/9 and a 3.12 ERA with filthy movement in his rookie campaign - ACE. ****s--- bed against two cake matchups
Stroman - 3.09 ERA and over 200 innings - ACE - **** the bed against a cake and very good match up the last two games
Only one you can argue is Mahle being the number 2 of that staff which he is. His stuff is good enough he shouldnt be struggling against the Pirates or Cardinals.
McCullers is unequivocally a #2 and borderline Ace who has also not taken advantage of a cake matchup and got destroyed by a middle of the road team.