In Europe we shoot sporting clays from low gun, or at least with the butt off the shoulder.

Clays are not the only moving target game. Anyone who shot running boar with a rifle or sight equipped shotgun, has to wonder about the suggestion to focus on the target hard enough to see the rings. In running boar at 50 meters you focus on the front sight, and most people hit the boar, many stay consistently on the kill zone.

Second point, if your eyes are on the target, how is lead established? By peripheral vision? If so what happens to gunfit that is meant to put your muzzles where "you look"? Where are you lookin when focusing and what are the muzzles pointing at?

Third point, is it possible to point ahead of the target and your eyes not focus on the sight reflexively? Eyes cannot focus on empty sky, os so some eye doctors tell me.

The issue is confusing. A look at the "quiet eyes" techniques developed by sports doctors for sports rquiring shooting accuracy, though no twith a gun, brings some fascinating angles to this topic.