I have one team in the AL, one in the NL. Both in pitcher's parks. Both use 13 position players and 12 pitchers.
In both cases, I always have one position player - a defensive utility man - end up with less than 100 ABs, and one pitcher - a short reliever in low leverage situations - end up with around 40 IP.
So I think the takeaway is that you can use those last two roster spots for whatever fits in with the first 23 best.
And yes, if I get into the playoffs I go down to 10 pitchers.