Here is my .02 on this and well, you get what you pay for. (should be pink)
Shoulder flexibility and ROM are great for preventing injury, for having healthy posture and have little to do with swimming ability/success.
The actual arm movement needed to swim is finally starting to come around (hence straight arm recovery) to NOT NEEDING TO BE SO COMPLICATED AND ARTICULATED. For years I have been trying to minimize the movement through the arm motion. Less stress on shoulder, less focus on "what is my hand doing" and thus opening up the opportunity to focus more on what matters.. that being breath and boat.
While I feel like I have said this before here, swimmers and swim coaches are now starting to discover (from watching elites) that much more forward propulsion can come from the arm ABOVE the surface, than any work that is being done under the water. Having your throw arm be extended (vs bent elbow) allows for more of a throw weight over the surface and that throw weight can have dramatic positive impacts on your velocity.
While this is true for 17.6 sec 50 yard free times... it applies to OW and distance swimming (ie triathletes) as well. And I would argue to even better effect.
good luck
daved
http://www.theundergroundcoach.com