I'd lean 12 pitchers, especially for the wild card round where you only need 3 starters anyway, so Assad and Rea probably get left off.
Pending the Tucker situation, you have your regular 9 plus a catcher (McGuire/Miggy), Castro, Turner, and then I think it gets interesting for the last 2 spots. If it was me, I'd definitely have Ballesteros on the roster and very heavily consider him as a starter over Seiya against RH starters. Those splits for Seiya are ugly. I think at that point, it probably makes sense to add Santana to the bench because of the platoon situation with Busch and Turner being as stark as it is. Having that versatility available so you can take advantage of a matchup late in a close game seems like something that could turn out to be a big key at some point.