I don't think it's speculation that the Sox would be better off with Shaw than Thornburg, at least in 2018.
There might be debate about Miley/Smith, but arguments can be made for both sides there, as well.
But the bigger names not in the bullpen, yes the Sox are a better team in 2018 with Sale, Kimbrel and even what's left of Pomeranz.
Now, when 2020 and 2021 roll around, hopefully we will have a WSC in the back pocket. Because the current farm doesn't look promising, and pitching staff will carry an extremely expensive and potentially declining David Price hogging up financial resources, and maybe a key starter like Bradley or Bogaerts heading elsewhere for bigger cash payouts, and this farm system does not look equipped to replace any of these players with anyone of even remotely the same caliber.
But a lot can change in 3 years..