What I meant was when someone takes a "one size fits all" approach to cross-dominance, they will be wrong sometimes. There are many different causes, and varying levels of severity. I agree with your Drill Sgt: Do what works for you.
Neuroplasticity will only take one so far. And it works better the younger you start working with it. When the eyes are anisometropic enough, neuroplasticity becomes hard to impossible to accomplish, without entirely closing the dominant eye. If there is emmetropia or balanced light refractive errors, either eye can become dominant, and it is then easy to change eye dominance. When the difference between the two eyes' refractive power goes beyond 2 diopters, the brain will choose the stronger eye as the dominant one. This is usually not corrected, as it only shows up in certain instances where stereoscopic vision is an advantage, like tracking a moving object. It only becomes a problem when the parallax induced by cross-sighting (having the gun on the right shoulder, but using the left eye to aim) causes the shooter to see two targets, or two front sight/beads. (or both) It can sometimes be corrected with prescribed prism, and in the case of amblyopia (lazy eye) which results in the brain rejecting the signal from the non-dominant eye, usually is done so early in life when the muscles controlling the eye are still developing, and the eye's physiology is more correctable.
It is possible to shoot moving targets without stereoscopic vision, but it
is harder to do. I've done it for about 50 years, but as mentioned earlier, there are times I do open both eyes to track game birds as the gun comes up.
This is a good introduction to anisometropia:
https://youreyesite.com/things-you-need-to-know-about-anisometropia/#:~:text=Anisometropia is a condition that,asymmetric farsightedness, or asymmetric nearsightedness.
I was introduced to it as a child.