Inbox: Best Rule 5-eligible prospect? Trade regrets?

Thanksgiving is here and I'm sure we all have things we are grateful for. Family, friends, the usual list that deserves gratitude. Personally, I'd like to share my thanks with the MLB Pipeline staff.
There's no need for details, but there have been some challenges to face over the past few weeks. One thing that made it easier to deal with was the knowledge that my colleagues at Pipeline, and MLB.com as a whole, had my back. Slack was picked up, trips were taken in my place, calls were made to check in. Without getting too emotional here, all of it has given me the time and space needed.
And I'm grateful for all of you. For reading and watching our stuff. And for, week after week, sending in great questions for us to answer in the Pipeline Inbox. Let's dig in like it's the pies my daughter made for this year's festivities.

The deadline for teams to set their 40-man rosters passed on Tuesday evening and that left a good number of prospects eligible for the Rule 5 Draft on Dec. 13. There are no Top 100 caliber players eligible, as all eight of those prospects were protected by Tuesday night.
As I discuss in the video above, there are four players who are in the top 10 of their respective organization's Top 30 lists:
Marcus Wilson, OF, D-backs No. 7 prospect: Wilson has a ton of tools and showed some of his power-speed combination in the Class A Advanced California League, but his overall approach regressed (his strikeout rate went up and his wallk rate went down compared to his breakout 2017 season).
Sandro Fabian, OF, Giants' No. 8 prospect: Fabian had finished his full-season debut in 2017 off very well, but wasn't able to carry it over. Like Wilson, his approach suffered in the California League and he finished with a 107/26 K/BB ratio.
Josh Ockimey, 1B, Red Sox's No. 10 prospect: Unlike the two outfielders, Ockimey has reached the upper levels and had some success there. There's a lot of swing and miss (149 K's in 117 games in 2018), but he also drew 70 walks and hit 20 homers while reaching Triple-A. He might be an interesting Rule 5 choice as a left-handed power bat off the bench.
Jake Gatewood, 1B, Brewers' No. 10 prospect: Gatewood has a ton of raw power and he tapped into it a bit more consistently in 2017. This past year, he did hit 19 homers, albeit with a 114/29 K/BB ratio in 94 games. Gatewood tore his ACL last summer, likely making him too risky to be selected.

Before I answer the question, the necessary caveat: Teams aren't likely to regret a deal involving a player who is still a prospect because that player hasn't done anything in the big leagues yet. Even if the return they got for that prospect (or prospects) didn't pan out, they could argue they took a shot and the Minor Leaguer(s) in question have yet to play a Major League inning.
That said, I think you're probably on the money. The White Sox sent Fernando Tatis Jr., along with Erik Johnson, to the Padres in June 2016, in return for James Shields. At the time, Chicago was just two games out of first place and two games over .500. The White Sox finished six games under .500 and 16.5 games out of first. Shields went 4-12 with a 6.77 ERA post-trade that year and is now 16-35 with a 5.31 ERA in 77 games with Chicago. Tatis, meanwhile, has turned into the best shortstop prospect in the game and is No. 2 on our overall Top 100. It's looking like that one will end up quite lopsided.
There are others that could end up in this conversation. Here's one that comes to mind: The A's got Jesus Luzardo from the Nationals in 2017 in a package that netted the Nats Sean Doolittle and Ryan Madson in return. Doolittle is still pitching very well for Washington. Madson was solid in relief at the end of the 2017 season, but scuffled this year before getting dealt to the Dodgers. The Nationals lost in the NLDS in '17, far short of their goal, and Luzardo is now the top lefty prospect in the game, one who should impact the A's rotation in 2019.

This is, in many ways, a question about philosophy in how to build an organization. In full disclosure, I tend to lean heavily in the "keep your prospects" camp, though I know that isn't realistic, nor is it practical.
The Padres are on the cusp of turning things around, getting some young players to the big leagues already and with the best farm system in baseball at their disposal. And obviously, there isn't room for all of those arms (well, I guess technically, you could create an entire staff from those pitching prospects, but that's not going to happen, right?) in San Diego.
The good news is there's no rush. While the Padres will undoubtedly improve, I see this more as a two-year process. Of course, I thought the same thing about the Braves in 2018 ... But I digress. If San Diego makes a huge step forward in 2019, then you can talk about trading those arms. For now, though, I'd let them develop. So many are far away, and while the inclination might be to trade them now, before anything like injuries get in the way, those who do make it to the upper levels successfully will have more value because of their proximity to the big leagues. Now, in 2020, that might be the time to see how things stack up and use some of the pitching depth to make a big splash at the highest level via a trade or two.

You've asked the wrong guy. I haven't eaten turkey in about four or five years now. I do eat fish (pescatarian would be the right term), but I don't eat meat. Back in the day, I was a white meat guy, though if that helps.