So you are citing Hollywood as a viable source?
This is a about the worst advice I’ve seen all day and falls flat on it’s face the moment you get of the bench and need to shoot and move with any quickness. The support hand drives the gun, not the firing hand. To constantly have the support hand manipulating the action means you’re having to break the position between each shot and then rebuild the position, which is incredibly inefficient to say the least. Which is why nobody who’s serious about it actually does it unless for to by extreme circumstances.
As to the solution, eye dominance can be over come fairly easy, and in some studies it suggests cross dominance actually seems improves processing speeds. But when it comes to hand dominance it’s best to stick with a matching action.