I would much, much, much rather have guys like De La Rosa, Morales, or Aceves who may not be able to throw 200 IP, but will give you 100 IP of 4.2-4.4 ERA baseball, as opposed to last year having a guy like Aaron Cook who can throw 200 IP but will give you 5.70 ERA.
If someone goes down for a full season, it may have to be a collaborative effort to make up his innings, or they can look externally at the trade deadline to fill the hole if there is too much workload being put on some of the fill in starters because, at that point, the fill ins still wouldn't have bumped up to their innings limits.
The fact that we have Aceves, Morales, and De La Rosa makes me much more comfortable with the back end of our rotation this year than I would be if we had Cook and DiceK back there. And it's not close. I actually feel relatively comfortable with the back 3 of our rotation right now, knowing we have some pretty talented guys waiting in the wings to take over in case of underperformance and/or injury.