Actually you've got it exactly backwards, horses that are built
uphill (front slightly higher than rear) have LESS trouble with collection,
are lighter in the front end, and are more suited to use as saddle horses.
This is universally accepted as the correct conformation for a dressage
horse.
Horses built downhill are built for speed, the more downhill the
shorter the race and the faster the horse. Typically sprint racers are built
very downhill, while Thoroughbreds who race Derby distance and longer are
built only slightly downhill. It is generally accepted that endurance horses
should be level or close to level, neither higher in front nor lower since
they have to be first and foremost saddle horses.
Tracy and everybody
Tracy Scheinkman
Misty Mountain Arabian Sport Horses
Tucson, AZ