The 5.5 WAR comment was me actually giving his value the benefit of the doubt. I was saying, at best, this is how much he'll cost in prospects. If we want a more tempered projection then it could be as low as 25 or 30 million in surplus value. I thought it was pretty obvious that I was making this point to address his likely prospect cost (which shouldn't be too high than), rather than comparing him to Brantley or Mccutchen from a quality standpoint. The main benefit of a Peralta trade is the money you would save. He's not going to make more than 7 million next year. So, yeah, you are sort of correct when you say that we'd use those saved resources to pursue guys who would fill other holes, the same thing we would do if we did the opposite and traded for Realmuto; those resources would go into signing an outfielder/bench/bullpen/whatever. I'm not sure why you are skeptical of us spending those saved resources. But purely from a baseball standpoint, I still like Peralta more than Mccutchen or Brantley. In the past three seasons, Peralta has been worth 6.9 bWAR and only played in 48 games in 2016. I know that 2016 injury seems concerning, but it was his wrist and he's shown no signs of any lingering issues. In that same time frame, Mccutchen has been worth 4.7 WAR. A lot of that has to do with him losing defensive value in CF in 2016, but still... I like Peralta's upside a little better. Plus Peralta is left handed and I think that balances the lineup out better. Brantley's flaws are more obvious. Injury history being the biggest one. He's a good player, but I'd also prefer to get a little more power in our acquisition. I also like Peralta's defense a little more than Brantley's in LF as well. I would also presume that any Brantley or McCutchen deal would involve a 3+ year commitment. For Peralta it would only involve 2, for less money. So yeah I'm willing to give up 30-45 million in surplus value to gain the perceived benefits of a Peralta acquisition. One thing that should also be mentioned: This particular offseason path would be ideal if we got Grandal in FA. That is one major reason to address cOF through trade. I think getting an elite pitch framer with a good bat plus a power corner outfielder would be a better offseason than trading for a poor pitch framer (JT) and signing a corner outfielder like the ones mentioned here. Not to mention the fact that this path would cost less in terms of prospects and probably money. So a Peralta acquisition would make far more sense when framed in this context.
As far as me dodging the question, I don't think that is what I was doing at all. You named several players so it was easier to just put a few in a "preferable" group and a few in a "not preferable" group instead of listing the pros and cons for each one. Schwarber would be expensive, but I think he'd be worth it in a lot of respects. He's actually not as bad of a defender as you're making out. In fact, he had pretty darn good UZR numbers last year after losing some weight. He's projected for 3.1 wins next year and I'd consider him an improvement over Markakis. The only question with him is cost. If we project him for 3 wins the next three seasons and he makes 25 million over that time frame, then he'd be worth about 65 million in SV. More than Peralta, less than Realmuto. So it'd just be a question of how much you like him as a player.
As far as the other guys go, Pederson is the next one that would make sense. And considering everything... it'd be close... but yeah, I actually do think a Pederson/Duvall platoon would be better if Duvall comes back and can hit lefties semi-well. We're talking about a guy that hit 24 homers in 380 PAs with almost a .900 OPS against righties. If Duvall could hit ~.750 OPS against lefties, I think that'd be a better outcome than Cutch or Brantley. Once again it'd all come down to cost. I'd have Pederson at about 5 wins over his next two seasons for ~18 million dollars. 32 million SV: not that bad.
There are also other guys who could become available and we could explore that you didn't mention. One of the bigger names that I think its possible we hear some rumors on is Joey Gallo. If he did become available, he would certainly be very expensive to acquire. 4 years of control at 3 wins per year... He'd cost us quite a lot. But it would be something to explore if he did become available. There are other names that haven't been mentioned as well, but this post is getting long enough as it is.