It’s an instance of folks trying to relate a simple concept and overthinking it.
I can promise you no one can come up with criteria for a #2 starter that isnt either ridiculous, or doesn’t include Sonny Gray. Honestly, the best definition I’ve seen in hindsight was the simplest - someone to start game two of a postseason series. (Points awarded to 5Gold) It’s impossible to quantify, but really, it gets across a simple point - “improve the rotation and do so by improving the top end.” I think that’s all anyone wanted. Now, Gray does actually do that. But I think he lacks the sexiness many wanted, and as he is already 36 years old and will very likely continue to get older, he is a short term solution at best.
But I like this rotation right now. The Sox have a rare level of depth we usually don’t see in December. If they don’t add another SP, I’m ok. Fix the infield and, since MLB is a bullpen game, add additional quality arm(s?) to the bullpen. And maybe a catcher, but thats low on my list…