I think that Maddon is wary of riding a situational pitcher too much. Ryan pitched out of a high-stress 5th inning and then, for another inning, asking him to finish off heart of righty lineup coming up, including Goldschmidt, is asking for trouble. Goldschmidt vs Ryan is a match-up to avoid.
The strategic move is to bring in the righty there. If we want Ryan to continue to do well, you have to pick your spots with him. Pitch him when he’s most likely to do well.
Obviously, Brach is walking way too many guys but if you’re going to opt for a lefty there (who already has thrown a high-stress 15 pitches), then there’s no point having Brach on the club.