Conformation is the overall shape of a horse and is variable between breeds in details such as average height and weight, overall build, refinement of head, etc, but to remain sound, all breeds must have the same basic correct conformation.
A horse may indeed have someone’s interpretation of a “game head”, but failure to recognise that this same horse may have limb conformation faults with the potential to cause unsoundness is a serious contravention of welfare.
Horses with EIPH are known as bleeders and may show a trickle or a flood of blood at the nose after a gallop or race.
In a performance horse especially, the neck must be long to allow for proper flexing at the poll, which is required in any performance event.
As viewed from the front, the horse should show significant width from shoulder to shoulder, a large circumference to the forearm, and a prominent "v" in the front muscling.
For performance horses, muscle mass should be no more than adequate to perform the tasks at hand, because increased muscle bulk detracts from the fluidity of the horse's stride.