Charlotte Dujardin came into dressage from the UK show classes that are judged on the performance of the horse and not of the rider - though a good rider will always get more out of a horse than a mediocre 'sitting pretty one.
Why not have similar classes that are aimed at 'riding horses' rather than what we see as dressage horses but are performing at the entry level standard using a 'general purpose seat - which is pretty much whats expected in a UK show class. We have lots of classes that are judged by type and not breed for ponies, cobs, hacks, riding horses and hunters. The classes involve riding altogether around the ring at walk/trot/canter and in some cases a gallop changing direction by riding across the ring and not 'reversing on the rail. Each horse/rider then does an individual show while the others are lined up to one side or in the middle of the ring and they are then judged.
There are the lower end local shows that anyone can enter in regardless of how much they paid for their horse and the higher level County shows
There is a championship class at the bigger shows where all the various types of riding horses - winners from the individual classes compete against each other,
Clip of a championship class at the Horse of the Year show
FOR EXAMPLE ONLY AND NOT FOR CRITIQUE!!!!