The problem is, this is the World Series. No matter how well they are pitching, in the modern era, how often do you see a starter go more than 6? Even if they have only thrown 80-90 pitches, as soon as they give up one hit or walk that deep in the game..... gone.
That said, if Maddon has less trust in his other relievers he could try to use Hendricks long enough to get straight to Chapman, but after Chapman threw last night, I doubt he'd could go more than 20-30 pitches.
If they fall behind early and it gets to Miller time, that's pretty much doomed the Cubs in the past, but we'll see.