As well as Fister has pitched, he's not a lock for the first series roster. There's no way he ever starts in the first series, and using him in relief is too risky to try in a playoff setting. We won't even need the 4th starter (ERod or Fister) except maybe in long relief of a starter who stumbles out of the gate.
My guess is a healthy Barnes would replace ERod or Fister.
You forgot to even mention Abad as a possibility. To me, he's a "given" right now.
I'm not sure Smith makes it, but we'll see how he does after he's called up. He's looking good in AAA. We could possibly start the first series with only 10 pitchers. We'll have had a day or two off before game one, play 2, day off, play 2, day off, play 1. Every RP'er should be available every game, unless used for 2+ IP.
I think we go with 10-11 pitchers:
Sale
Pom
Porcelo
ERod over Fister (my guess right now)
Kimbrel
Reed
Kelly
Workman
Scott
Abad
Barnes or Smith possible (Fister maybe in series 2) or just 10 pitchers series 1
C: Vaz & Leon
1B/DH: HRam & Moreland (Nunez)
2B: Pedey & Nunez
3B: Devers
SS: Bogey
LF: Beni
CF: JBJ
RF: Betts
Bench: Davis Holt, Young
Possible: Brentz, Lin, Marrero, Butler (to allow PH'ing for catchers)
With Holt and Nunez as back-up IF'ers and no IF'er in need of a PH'er late in the game, I don't see much hope in Lin or Marrero making it, unless Pedey has to DH some.
The most likely players to need a PH'er or PR'er late in a game are:
Leon
Vaz
Moreland (vs LHP)
maybe Beni (vs LHP), but this hasn't happened that I know of so far this year.
To me, if we go with just 10 pitchers series 1, a third catcher should be in strong contention for that 25th slot. Even if we go with 11 pitchers, I could see us going with Davis over Young, and since we have Holt as the 5th OF'er, we could go with Butler over Young.