Yeah, the Brewers system has some projectable arms, and coupling with young pitching already up in Milwaukee, looks pretty darn good....but it's crazy depth is in up the middle, toolsy position players. IMO, Pena alone plus another top 100 Brewer position player prospect is much more value than what the Dodgers sent to Detroit (some value analysis of the hypothetical trade package scenario that had both Pena and Henderson in the package had it around 117, while the actual Dodgers package Detroit accepted was like 24).
If Detroit was insistent on getting multiple arms, or 1 MLB-ready young starter back in a trade for Skubal, the Brewers weren't going to give them that for 2 months. I'm more or less convinced the Tigers took a less valuable package for Skubal than whatever the Brewers would have offered, knowing that's where he wanted to be traded to and because they wanted more pitching back than what the Brewers were willing to give up.
Tinfoil hat time, it wouldn't surprise me in the least for Skubal's agent (Boras) to weigh in with various GMs in on the Skubal sweepstakes, indicating he's either going to the Dodgers or he'll shut himself down for the rest of the year to avoid another arm injury before he hits free agency (since it's likely the Dodgers who will sign him anyway).