I am in a theme league based on seeing how you can use 700 + IP pitchers - MLB99753 - and I know that several of the owners are using 2-man rotations. You might want to take a look and see how they are doing.
I went with a variation - I found two starters with the most, and highest ratios of complete games I could and put them in an A/B combination.
So essentially it is a 2-man rotation with 3-men, the 700+ IP pitcher, in my case Matt Kilroy 1886, pitches every other day, without putting that stress on the other starter who, being two people, pitch every fourth day.
But as Trentonjoe says, it is all about the pitch count which is what I was trying to deal with by going for the complete games as a criteria for the other starters.
Mostly it has worked ok, though once one of the A/B starters was fatigued and I threw in someone else into the A/B rotation for a round or two, then switched them back.