Good points, longwinger.
As regards slinging, one's dominant eye does not play as prevalent a role in shot determination, at least from the perspective of parallaxial triangulation, as it does in archery. I perceive that, with the sling, it has more to do with how information is visually processed.
For instance, if a person is accustomed to looking at the world largely through one eye specifically, that eye will appear larger, it will be open more fully than the other....some have what is called 'lazy eye' where that eye is hardly open at all.
There are certainly a large number of variables which come into play regarding the visual processing of information. I consider that one whose eye/hemisphere relationship is most optimally developed for processing the massive amount of data necessary for accuracy exercises will find more success.
One's reaction time is very important in skills like the sling....absolutely critical in fact.
Imagine two 'parallel computers' networked together....one specializing in the processing of object information the other in relationship processes.
The total system 'reaction time' would be slower if data best assimilated by one 'cpu' had to wend it's way over after first being input visually through the other.
It has been shown that 'lateral thinkers', those whose inter-hemispherical connections are more robust....are able to process data more effectively. This is rather like increased 'bandwidth' between two 'parallel computers'.
Ideally, a left handed, left eye dominant/right brained individual, may in fact represent the best slinging potential.
But of course.....I'm 'splitting hairs' here.
As variances by minute fractions of a second are translated from micro to macro scale during the sling cast, many millions of variables are being physically reduced to a critical moment. If indeed the right brain is largely responsible for the processing of accuracy exercises, and a preponderance of evidence seems to suggest this, then a fully left side dominant person would represent the aggregate optimum.
I would also venture to assert that an accomplished slinger could translate his associative skills into a host of other areas of life.
I have had interesting results in covering my dominant left eye using a sling as a makeshift eye patch. This forces the left brain to process more visual information. As it may be well nigh impossible and perhaps not worthwile to try and fully eliminate noticeable eye dominance, I can imagine that occasionally covering either eye may induce a more productive inter-hemispherical relationship.
Beings how I was forced to switch to a left handed bow in archery sport due to a severe lateral curvature of the spine induced by so much practice with a heavy bow.....I have found, after much practice, that I am a better archer now....in harmony with my left eye dominance.
BTW, for those interested:
One can easily determine eye dominance by pointing at an object on the wall, looking down your arm, staring at the target and then closing the right eye. If your finger jumps off target when you do so then you are right eye dominant....if not then you are left eye dominant. If you have trouble deciding which of the two seemingly semi transparent fingers floating before you to place on the target......then I would like to study you with my admittedly rudimentary, portable MRI machine......(lol)