Just thinking about the above, I had always assumed that horses stand equally on four feet. Their feet gathered under them as legs under a table.
Going thru the internet, I understand that the above is not quite true.
Many horses rest one of their hind legs when standing. Usually the hind legs because the hind legs are longer than the fore legs.
And when horses graze, they usually put one front foot in front and one behind.
A horse standing clawed out all feet wide apart is an unnatural stance, suggesting conformational problems.
The interesting things you read.

Pinterest has lots of horsey refs that help, eg

https://www.pinterest.co.uk/pin/465841155192393360/