Heres what their projected rotation looks to be.
Now at first glance the rotation seems poor, but two of their pitchers could be inline for a breakout year. Look at William Liang if he can continue to develop he should become a front of the rotation type of pitcher.
If we also take a look at Benny Morales we see someone with not a lot of control, but decent splits. If he can put up an ERA in the mid to low fours you'd have a pretty effective number four.
The other two appear to be more of inning eaters, and veteran guys. If there is one thing you do not want to do is shove a bunch of rookies out into the rotation, this could prove disastrous for the rookies. The mullets appear to be taking the slow tiny steps to an average rotation.
Further look at the minors we see a variety of prospects that if they developed could turn out to be solid pitchers. While only two scream front of the rotation to me, and most shout middle rotation, having the pitching prospects that the Mullets have is a luxury in a league that is deprived of pitching.