I will clarify the Arabian Warmblood thing. In Australia, there is the Purebred Arabian Studbook and the Arabian Society some years ago started an Arabian Derivative Studbook. An Arabian Derivative pre-August 2012 only had to have Arabian in their pedigree, no matter how minute and catered for the following breeds Arabian Pony, Arabian Riding Pony, Arabian Warmblood, Quarab, Arabian Stockhorse and Part Bred Arabians. Come August 2012, the Arabian Derivative Studbook was restricted by the Society that oversees it to new registrations for Arabian Warmbloods that had a minimum 12.5% Arab or both sire and dam were already registered, now allowing a window for a small amount of low % Arabian Warmbloods to still register. I cannot speak for the other Arabian Derivative breeds, there were changes across the board, as I am only involved in the Warmbloods.
The probable motivation into opening an Arabian Derivative Studbook was to commercially support the Society when Purebred Arabians were struggling with registrations and show numbers some 20 years ago (I may have this wrong but this is my understanding). They have their own rings at the Arabian Breed Shows and are amongst some of the best shows to compete at. An Arabian Warmblood registration for us is a ‘secondary registration’ to the normal Warmblood rego for Showing.
I have two horses registered Arabian Warmblood, W.Ellington whom is mentioned above and a Quaterback mare. The changes to the studbook mean I cannot register any more youngstock, but as my horses train on their focus is Dressage.
As to presentation, present as you see the best for your horse. What we do works for us and gets us fantastic results in the Show Ring.
To the OP, we have a Hollingrove horse as well