Pitching wise they've held up about as well as they can under the circumstances. Bullpen has performed well and they have gotten some reasonably good performances out of guys who needed to make steps coming into the year (Lange, Jimenez, Foley) as well as guys who weren't even on the radar going into camp (Vest). And regardless of how quality one thinks a lot of the young starting pitching in the minors can potentially become (guys like Brieske, Faedo, Hill or hopefully Wentz when he gets some starts), there's been enough of it to keep the wheels from flying completely off the cart for the most part.
Where Al deserves criticism is on the position player side.... obviously no one could have foreseen Candy, Schoop, Grossman (he deserves mention) falling into obliviion or Meadows injury, but by this point in the rebuild, one clearly would expect that they would have more options at the upper tier of their system, particularly in AAA, that could really push for playing time at the bigs in a pinch. And that hasn't happened. There's Carpenter who, despite his meteoric rise, still lhas reason for skepticism and Kreidler, who hasn't played much this year because of a fractured hand.
Put another way, if the Tigers system had the kind of talent at the upper ranks of the system that the St. Louis Cardinals have (among others), they would have had more options and flexibility to deal with the trio of players whose offense fell into oblivion and Meadows being incapacitated most of the year. But they do not.
I've been watching 84 Lives for days (in multiple threads) talking about a lot of the prospects and I hear him and all, but even if one feels like their drafts have been better the past couple of years and that they have brought some guys in who have reasonable enough chances for success moving forward (such as Pacheco, Jung or Graham), these guys are still years away. Even a lot of the guys who have seen performances pick up, such as Wenceel Perez or Parker Meadows, are still in AA and all still seem to warrant skepticism. So aside from hoping that Al gets canned, we're kinda left living off lottery tickets for at least the next year and a half and hoping a couple of them pan out lol