First, the FO went into 2016 with Travis Shaw at 3B and Rutledge as the AAA call-up depth behind him with no real platoon intentions, so while you might not be a fan the FO opted for that when Moncada was much more of an unknown and Rutledge didn't have the solid stretch of play he put up this season.
Second, the wRC+ you're citing for Rutledge is largely the product of 1. his career starting in Coors (with a meaningful negative correction for park factor in 2012 and 2013) and 2. his 2013 season having a wRC+ against LHP of 25. Every other ML sample is above 90.
Beyond Rutledge, why exactly is Brock Holt, a player with meaningful reverse splits in 2014 and 2015 and only 36 PA against LHP in 2016, not a reasonable option? He's going to likely be back to his super sub role and plays a solid defensive 3B. His career .718 OPS against LHP would put him between the general production of Martin Prado and Brett Lawrie for the 2015 season by wRC+ and wOBA, almost exactly tied with Travis Shaw's wOBA and wRC+ non-split production for 2016 as well.
And why is Witte not worth even considering? The entire hope when drafting him was that he'd advance quickly and hit LHP well enough to be a platoon candidate. Turns out he's done exactly that. All I can assume is you're applying the same kind of pedigree standard that had people opposed to even trying Travis Shaw out last year. Turns out all recent data indicates guys who are passable Pawtucket hitters can actually produce at the ML level (same for Bryce Brentz, who didn't embarrass himself by any means when called up and in fact hit pretty close to his AAA numbers). Witte will have had almost a full season of AAA ABs next year.
Sam Travis isn't an option here either? I mean, the guy might have been the best all around hitter in the farm system prior to tearing his ACL. He isn't an NFL running back or something so while the ACL is a set back he was on track to be the starting 1B to open 2017, now he doesn't belong in the conversation as RHB depth for a platoon setup?
Lastly, you think relegating a top 20 prospect form just a few months ago to a backup C or 5th OF/3rd C role is good use of talent? Swihart got pressed into early service and had his development rushed because of the 2015 injuries, leading to him effectively skipping AAA. His last meaningful mL sample was AA where he posted an .840 OPS as a catcher when he was 22 years old. Swihart also is a natural right hander who has a substantial LHP bump in his meaningful mL sample sizes, likely a result of him only adding switch hitting near the end of high school. Meanwhile the scouting rap on Moncada has always been that his LHB approach is better than his RHB approach. Almost all other catchers are RHBs or switch hitters, so there is limited value in a catching platoon. So if the Sox are thinking about Swihart in a utility role why wouldn't they have him add both corner IF positions to the repertoire, letting him be the long term backup to Moncada, Benintendi's platoonmate, etc.?
This for a club that is already heavy with guys who crush LHP, and with the only substantial offensive loss being a LHB who, while elite across the board, has a substantial split. Who platoons with Shaw and/or Sandoval at the corners against isn't the problem with Papi's retirement, it's how you replace 350+ PAs of 1.000 OPS hitting against RHP. They probably don't, so do you throw a bunch of money after it hoping to band-aid what might be a non-problem or do you let the organizational depth do it's job and fill gaps like a ~100-150 PA platoon roles?
The answer should be pretty obvious because they aren't getting someone like Martin Prado for less than they gave Chris Young, and unlike with Chris Young they aren't unsure if they can even field worthwhile starters at the corners.
I was fine with how they went into 2016, please don't assume. I thought it was too soon to sell low or cut bait on Panda, we still had Ortiz' bat in the lineup, and Shaw had looked promising in a limited sample in 2015. A year later, we have a year less on Panda's deal, Shaw has shown that he probably has more of a traditional split than he did when he first came up, and we have one less David Ortiz than before. Times have changed.
And look, I think it's very possible that we go into the year with some combination of the options you described and that it's not the end of the world. But I also think that with Ortiz retiring the overall composition of the roster could shift towards one without a full-time DH, and that there are potentially options for making that move in 2017 without blocking Moncada while still having a bit higher floor in terms of performance. If those options are explored and don't work out, fine, I will still have high hopes.
You say that we aren't getting Prado for less than Chris Young money. I agree. In fact, he might cost more than CY did. We might not get him at all if he's looking for more guaranteed playing time, and that's fine, but if I could sign him tomorrow for 2 years 10M to play 3B against LHP and back up OF/2B, I happily would. With all the money coming off the books, that's exactly the kind of stop-gap signing that a big market team can afford. He can still be dealt if Moncada is ready (or he can turn into a platoon partner to ease Moncada in if, say, Travis is up and Shaw gets dealt).
The rest of the disagreements are mostly academic or semantic. Sure, invite Witte to ST and see if he gets hot, why not - I'm just not counting on it. I didn't include Travis because I was not under the impression he could play 3B, and him coming up to play 1B doesn't change the situation at 3rd. I don't understand why we would bother to parse Rutledge's measly 300ish PA major league sample against LHP year-by-year, and anyway, even if it's a touch more optimistic as you suggest, that's probably not enough to cover for the fact that he seems to be a horrible fielder at 3B. And did you really compare Holt's splits against LHP to Prado's and Lawrie's full-year stats in a discussion about who will face LHP at 3B? I guess you are trying to say that a .700 OPS and decent defense at 3B is acceptable since some other teams are getting the same? Again, I think they can do better without mortgaging the future, and while we might be able to carry that kind of production this year, next year's offense is still a work in progress.
I was unclear re: Swihart. No, I don't think his ceiling is backup C. What I'm saying is, I think he has a good chance of being needed at C / OF in Boston soon, and potentially for a long time if he develops as hoped, and I would like him to be ready for that. I don't think he will be needed at 3B and I don't think it's a good use of his remaining developmental opportunities to break him into another position. It's not that he couldn't do it, it's that he probably couldn't do it fast enough to be the stopgap you need, and trying to teach him would take away from his learning opportunities at C.
Finally, I completely agree that replacing Papi's production against RHP is a bigger issue (just in terms of # of PAs) than who plays third against lefties and how much marginal improvement we could get there without going nuts or breaking the bank. Which is why I was specifically interested in a scenario where you add a guy like Prado AND a Brandon Moss type guy. You can probably add both for less than the AAV of a guy like EE, and certainly for shorter money, still leaving resources available to extend the kids and make some improvements in the bullpen. And even setting that aside, runs created by our 3B against LHSP count just as much as runs created by our DH against RHP. It is a smaller number of PAs, but I was thinking about it in terms of a holistic roster management strategy.
