The Cubs came into the season with the following options at starter: Steele, Imanaga, Taillon, Boyd, Assad, Rea, Brown, Wicks, and Horton. 3 of those players are injured long term, Brown and Wicks haven't worked out in a starter role (I question why both of them have both taken a step back after looking really solid at times last year). Flexen was probably always seen as a long relief guy rather than a starter but I guess he was an option too.
I can't remember if Assad was the favorite for the 5th starter role before he went down but I would have pegged him in at 5, meaning 3 of Cubs projected rotation has missed significant time. Rea has been better than expected, Horton has had some bumps but has mostly held his own. You really can't ask for better from your 6th and 7th options. The issue is Brown/Wicks have not worked out as an 8th option.
Maybe Milwaukee would be fine if they lost 60% of their rotation, their pitching infrastructure makes ours, which I would still consider among the better ones, look amateur. But the fact is, if your ace misses the entire season, your number 3 misses multiple months and your 5 has missed the entire season so far, most teams are going to struggle with depth. The good news is the Cubs have the resources to go out and change that. Jed needs to put on his big boy pants and treat a win now year like a win now year.
The other question consideration is, does Craig need to manage with more urgency? I'm not even saying I agree with this, it's just a question I'm asking. He's been elite historically at managing his rotation to keep guys sharp through the season so it's hard to question his methods. But the bullpen game against the Yankees could have been avoided. The off day on Thursday could avoid another one if they wanted. Again, I understand why Craig wants to give guys like Boyd and Horton extra rest and it makes complete sense, I'm just saying that a more aggressive manager might be skipping the 5th spot in the rotation when possible.
But the final point is, the Cubs are 28-20 over their last 48 games. That's a 95 win pace, covering roughly 30% of a season. No reasonable person would expect to lose 7.5 games in the standings during a stretch like that. But these questions are coming because the Brewers are playing historically great over that same stretch. If they played in the AL Central instead of Detroit, no one would be complaining about Jed not building more rotation depth or not being more aggressive about swinging a trade ASAP. That doesn't make Matt's points invalid, we play in the NL Central so its very valid, just saying that we can't overreact too much or question Jed's entire team building philosophy with a team that is 1 GB the best record in baseball, they just happen to be behind another NL Central team.