I would have rather seen Duffey first, then Harper if Duffey had struggled. Or had thrown Dyson in the 7th and seen what he could have done. Yes, they need to figure out other pitchers in the pen outside of Rogers and Romo, but this wasn't the matchup for Harper to start the inning last night.
Duffey and/or May is the key the rest of the way. Dyson had a good outing but want to see a couple of more before putting him in the box with Rogers and Romo. If one or both put it all together in August and September, they might have enough.
Plus.... Thorpe is capable and there is the rumbling of potentially bringing up Graterol to help as well.
Of course it could have been worse, they could have signed Kimbrel (Twins were wise to pass on him)