C for me.
If Matt Shaw is truly coming around (and I think he is) then the price on Eugenio Suarez was too high to get such marginal improvement. In such an environment, Willi Castro probably was the best position player available to fit our needs. So getting him is a big plus. I'd have also liked a Harrison Bader or Ramon Laureano as a lefty-mashing bat for the OF. But that's going to be a very marginal thing over the remaining games.
Our big need though was pitching. I like Soroka more than most, seeing him as a bad #3 or good #4 in a rotation. But our playoff rotation now looks like Boyd - Imanaga - Taillon - Horton. That's probably a fine if unspectacular playoff rotation. But two of those guys have been dealing with injuries this season, and the other two are already way past their recent workloads. If any two of them drop and we're seeing Soroka/Assad/Wicks as our #3/4 in a playoff series, we are in real rough shape.
With respect to the bullpen, I anticipate our biggest add will be Ben Brown. I like his stuff playing up in short relief. If the rotation somehow stays healthy and Soroka spends time in the bullpen, he could make a difference as well. I'm just not counting on that. I don't think much of Kittredge or Rogers, but they should hopefully limit the blowups and give Counsel a little bit more ability to rest guys like Keller, Thielbar, Brasier, etc... So I'm okay with the pen. Would have liked to add Bednar or somebody, but honestly Ben Brown could be that guy.