I take Cherington at his word that the Red Sox are done shopping for now - makes more sense for the trade market to open up instead of being wed to Hamels (or anybody else) right now. Both Castillo and Betts have options, so the team can either A) start with one of them in AAA or only bring 11 pitchers up north if none of the outfielders get moved in the spring. (Obviously Bradley has options too, but I am assuming he is not a part of the big league picture for now)
The willingness to move Swihart will be dependent on the usual things - how desperate they are as shoppers, how well Swihart plays and how well Vasquez plays. I mean, if Swihart crushes AAA and Vasquez delivers a .600 OPS sort of season, the front office will have to make a real decision about where the future is. That might involve taking a plunge with a guy you have not seen in the bigs - that is why Cherington gets the big bucks, to make such a leap.
Very clearly, Cecchini, Bradley, Merrero, Coyle and the middle class pitchers are the first batch of trade fodder the Red Sox will offer. Very clearly a team with an asset like the Phils will be looking at the Sox Top 100 entrants. To me, it is clear there is a position player surplus - enough of one that solving that represents an optimal use of resources.