That looks like a fun pair of arms :-)
Yes, if you already have a known pose, choosing a solution that minimizes movement is a decent choice. The obvious draw-back is that which choice is made for a particular pose then depends on history, which may make validation harder.
Another choice would be the one that minimizes the torque (because of gravity/load) on the weaker servos. I notice that you use a MX-28 in the shoulder, but AX-12 in the elbow. With the weight of the gripper and load, and the length of your arms, you should probably not plan on lifting any great weights in that configuration!
I was asked to elaborate on "obvious draw-back."
When validating that a mechanical system is safe to use in a particular environment, such as around human beings, you need to be able to validate that the system will never be in a "bad" configuration. When the configuration of time T depends on the configuration in time T-1, then you can't create a closed-form formula that describes exactly where the system will be for a given set of inputs, and thus validation degrades to either assuming the most pessimistic assumptions (everything within the theoretically possible movement range will happen,) or you have to degrade to manual testing, which is notoriously bad at finding rare edge cases.
Similarly, when something goes wrong, you're going to have a hard time reproducing the conditions for the failure, so that you can study them, fix them, and then add some kind of test to make sure the failure will never happen again. If the pose of an armature is dependent not just on known current inputs, but on all inputs that have been fed to the robot since power-on, you're going to have to log and study a whole lot more data than if the pose is "closed form." (For simple time-dependent systems, storing just the output state of time T-1, and the new input state, may be enough to reproduce movement -- consider this for your system.)
Another option is to say "the system is weak enough to never hurt humans, and it's only for cosmetic display, so if it breaks, there's no money on the line." That's a fine way of doing systems analysis. In the past, I've designed systems with MX servos, that, because of a bug, moved into interference (stalled against themselves,) and before I could cut power (a few seconds,) the delicate Maxxon motors in those servos had already burned out their brushes, necessitating a $90 replacement for each servo motor. There is an "overheating" and "stalled movement" safety in the controller for the servo, but the timing for those safeties is 5-7 seconds, and the timing for burning out a motor at the highest rated voltage of 4S LiPos is more like 2 seconds...
So, validation is not just about keeping humans safe, it's also about saving money. To avoid this, you'll have to guarantee that no link in your arm will interfere with (be blocked by) the body of the robot, or another link of the arm, when you do the iterative solution. When using a closed form solution, you can bake that guarantee into the solution, and rest assured that there will never be such a problem.
All in all, iterative solutions are SO MUCH SIMPLER, and also often "look better" aesthetically, so many solutions end up doing just that, and living with the, now obvious, draw-backs related to validation :-)
(Please accept this answer if you find it to be helpful.)