The Swisher plate discipline argument is good within a team framework. The Red Sox abandoned that framework several years ago, and can't reassemble it at short notice. Rebuilding plate discipline and out avoidance will take several years, and in the meantime, this will be a free-swinging, aggressive team, and the front office should roll with it.
Plate discipline is not something that works only if other people are doing it too (though obviously it works better the more people are doing it). A guy on base is a guy on base, and a 6-pitch plate appearance is a 6-pitch plate appearance, and both have inherent value.
Also, the argument that "what Swisher does best....is to bat RH against LHP" may be technically true, but only by a modest margin, and as a characterization of him as a hitter, it's seriously misleading. His career wOBA vs. RHP is .353 (vs. .373 vs. LHP), and in two of the past three years it's been over .370. There is not even a shadow of a platoon player about Swisher. He's a true switch-hitter.
Finally, you may think that "this will be a free-swinging, aggressive team," but the Sox FO clearly disagrees. They have, in the past six months, abandoned two starters with abysmal walk rates (Crawford and Aviles), and of their offseason acquisitions so far, the only one with a career walk rate below 10% is Victorino at 7.8%. Napoli and Ross both have career P/PA over 4. Gomes has been at 3.9 or better the past three seasons. Whatever they have been, the Sox are clearly trying to become a selective, grinding, pitch-count-spiking team again.