Look, to advance, you need to win both Game 4 and Game 5. Stras would start one of these. The big question is do you like Roark on the road and Stras at home, with Gio for early intervention if needed, more than Stras on the road and Gio at home, with Roark as a multi-inning guy. Game 4 is no more important than game 5 for advancing. Sure, there's no game 5 without winning game 4, but this is not about getting one extra gate at Nats Park. You need a strategy to win both.
So, where do you want Stras to pitch? Who do you like better, Roark or Gio? Those are the real questions.
For me, I think it is close to a coin flip. Something suggests to me that Roark on a short leash, with Gio available for 3 or so innings, might be the best strategy. More important than who we pitch is whether we can get to Arrieta early.