Crochet, Fedde and Flexen produced about 11 bWAR over 83 starts (427 IP). Cannon, Martin, Burke, Thorpe and Bryce Wilson were good for about 5 bWAR in 52 starts (341 IP). It doesn't really work to triple the latter numbers and say we're good for 15 bWAR in 156 starts. I think the new 5 can put up at least as much production as last year's starting rotation, even throwing in Clevenger, Soroka and Nastrini's travails. The top starters aren't as good as Crochet and Fedde, and the back end won't be as bad as Soroka, Clevenger and Nastrini.
I would also expect Baldwin, Ramos, Vargas, Sosa, and Meidroth to put up a little more offense than the trio of Nicky, DeJong and the clown car of AAA utility infielders. Why? Growth. Higher ceilings. Regression to the mean. That alone, like the "Chicago White Sox" guy pointed out a short while ago, a team of replacement level players (AAAA) would be expected to win about 48 games. I think the top 4 of our rotation are somewhere between replacement and average ML player (0-2 WAR).
Last year's team was uniquely bad. That's why they set the record for losses.