I've always felt it is a losing strategy to try and upgrade your 4 or 5 SP'er. It's not a bad idea to add starter depth, but the best plan is to upgrade at the 1 or 2 slot, maybe 3 slot, if that is the best you can do. That pushes your current 2 to the 3, the 3 to the 4 and the 5 to depth. In a sense, it upgrades 3-4 slots with one add. In reality, it's just one guy, and you have 5 starters who all start 31-33 games, if heathy and not demoted, so it is just 1, and your 1 starts as much as your 4.
The #2 guy in the playoffs is a good way to look at it, but our #2 might be another team's #1 or #5, so in the context of the whole league, categorizing pitchers as 1,2,3,4,5 is always complex. As a general rule, I like to say the 30 best pitchers are #s, the next 30 are #2s and so on, but what stats to use and what time frame to use complicates that process, too.
To me, we have this right now:
1. Crochet (top 5 of 30)
3. Gray (looks like a 2 in many areas)
3. Bello (looks like a 2 in some areas)
4. Sandoval (health concerns)
5. Crawford (health) Dobbins (inexperience) Harrison (inexperience)
7-8. Criswell
Unknown: Tolle, Early, Perales
AAAA depth: Uberstine & Drohan