[lightarrow]

Well, I was only thinking of moving them a few meters  []
 
You know the distances between A, B and C. You don't care much when B and C departed and arrived. All you care about is that their accelerations (according to their own times) were the same.
 
When they stop at B and C, they should be equally dilated with respect to A. If they are not, we have a problem!

The phrase I've coloured in blue of your sentence could be taken as postulate, which is equivalent to say that the one-way speed of light is isotropic.
Let me try a metaphor: two  equal boats, B and C starts (simultaneously) navigate on a river in opposite directions, from the same harbour A, at the same exact accelerations (measured through their engine's powers) with respect to their inner clocks, initially syncronised.
After one hour, boat B is still at harbour A, while boat C is 1 km away. How's possible?
Hint: river current.

[CPT ArkAngel]

news!

http://www.physorg.com/news/2012-03-faster-than-light-particles-cross-check.html

[yor_on]

Heh, maybe I'm wrong? If we limit ourselves to SR I have found this guy ValenceE suggesting using entangled 'photons, and only one clock, but by splitting the photon in different paths using it as both the start and stop mechanism.

Maybe, First I thought, no, as there was two paths involved but thinking again I'm not sure that it matter for this. Remember that this is SR, involving no gravity in any of those paths.

What do you think?