Works for both sides. Tampa has pitching out the wazoo and is looking to add another stud young hitter to complement Longoria; Kansas City is needlessly trading any prospect who's been even slightly behind schedule in order to fill their roster with average-to-good players at their peaks.
That is to say, it works for both sides if you agree with Dayton Moore's nutty roster construction. Seriously, trading Myers, Odorizzi and Montgomery for James Shields and Wade Davis is basically saying you don't believe in those prospects reaching the potential everyone else thinks they can hit.
As Dave Cameron tweets:
I'm as big a James Shields fan as there is, but Royals needed to get more good players, not turn good players into other good players.