Much like we can save gear transmog styles as ensembles in the wardrobe, we need ensembles for horses we can save and also tie to the 5 wardrobe ensemble slots. It’s a bit of a PITA to have to reconfigure mount and accessories to match whichever of the 5 character ensemble slots I might be at any given time.
Blizz noted. Release that soon ( Maybe Season 15 ? )