Before you can conjecture about what the Tigers should do, you have to thoroughly and thoughtfully consider where they're at, at each position, with their current players. I hope others will find this review helpful or useful in arriving at their own ideas of what the team needs are and what they should do about them.
Let's start with the starting pitching rotation. Kenta Maeda is a big addition, yet we lost Eduardo Rodriguez, a lefthander, and a stud too. I like the addition, but hate the loss of Rodriguez. In any case, it is likely a wash - no drop off, but not a big gain either. Tarik Skubal is the best hope to emerge as a big difference maker in 2024. He's lefthanded too, so it helps to have him in the rotation simply from that side. However, his stuff is what I'm excited about - he could vie for a Cy Young Award if he stays healthy and can dominate over an entire season, as he's done intermittently thus far in his career. I think our best #3 starter is Reese Olson. He's young but was quite consistent in his rookie campaign. Can he get better in year 2? I'm hopeful and like him quite a bit. After #3 things get a little dicy. Matt Manning likely should be considered the team's #4, but he is coming back from a foot injury and may need time to fully recover even after spring training. Regardless if he is or isn't ready, he's had a lot of inconsistency so far in his career. The stuff seems to be there, but can he stay healthy and put things together for a whole season. I hate to say it, but I think he's just not ready to depend on that much yet. Likewise, Casey Mize should be nearly ready to resume being a starter, but it's definitely not a sure thing just yet. 2024 may be a year of recovery and getting back into the groove, so to speak. Sawyer Gipson-Long is another pitcher that will audition for a starting role. I thought he came out of nowhere last year and did a good job. I could easily envision him being a #5 man in the rotation, but since Manning and Mize may not consistent as a #4 just yet, could he be pushed up in the rotation? Joey Wentz, a left hander, just didn't put things together much in 2023. He's hardly mentioned in articles about how other view the starting staff, and I'm inclined to not give him much chance to be in the rotation either. Perhaps he becomes part of the bullpen? Ty Madden, Wilmer Flores, and Jackson Jobe may make appearances during the year too, but I don't think any of them will lay claim to regular role just yet.
The Japanese free agent pitching prospects I think really should be targeted. One or both of Yashinobu Yamamoto and Shota Imanaga. Imanaga is a lefty and probably a more reasonably priced option. I can hope that the Tigers see the value here and bring him on board for 2024. I think he would step into being at least our #4 starter and prove to be a stabilizing force for the next several years. Yamamoto I think would be even better but I think the Yankees have him in their sights and won't relinquish signing him. Still, there might be some case that can be made that the young Tigers with Imanaga and Maeta might make a more appealing situation. Unfortunately, I am not that optimistic. Getting Imanaga would still be a great Christmas present!
The bullpen is even less complete perhaps than the rotation. We have several pieces of the puzzle, and I'm inclined to want to keep them all, rather than deal any of the players away. Steve Lange, Jason Foley, Tyler Holton, Beau Brieske, Mason Englert, Will Vest, and perhaps even one or two others are promising performers. Maybe Joey Wentz provides another left hander, but it still seems that the bullpen needs much more from the south paw side to be deemed complete. There are quite a few older free agents that should be considered. I'm not overly excited about which one really, given that I'm more inclined to hope a rookie emerges from the Tigers' system sooner than later.
Summarizing my thoughts I really hope to see the Tigers succeed in signing at least one of the two top Japanese starting pitcher free agents. This would open the door to future signings from that league too. I think such an addition would simply be the smartest and be the quickest road to improvement.