I actually think there are more than enough innings available based on the Dur/Sta combos, IF the pitchers were of good ML quality. Particularly with lower quality guys like 1, 13, & 14, they don't really belong in the ML, so when they pitch there, it takes them more pitches to get through every inning, thereby decreasing the number of innings they can log. If the full staff was close to 2, 5, 7, 12, then I think it would be effective.
That said, silentpanda is correct that it would require micromanagement to some degree.