Never mind. If you're a Western Pleasure horse, or any other poor unfortunate American animal being displayed in the show classes on the lunatic fringe of American equestrianism, it doesn't matter if your own tail's a bit stringy. You too can get a custom made tail. Amazingly, this is perfectly acceptable in show classes.
Not only that, some breed associations even allow you to weight the tail extension to flatten the horse's tail carriage.
If your horse still isn't looking right, you can try a forelock extension.
It makes the diamanté browband look rather tame.