Yeah, if I’m considering upper level horses, this doesn’t bother me- it’s the human equivalent of running doubles. One outing is easy cardiovascular, the second is the workout. Presuming that the horse is fit for the task, attention is paid to appropriate recovery in between, and the horse has the equivalent of a physical therapist on tap, this can be appropriate exercise. If I’ve got a horse who could reasonably be in the final four of the USET and jump 5 rounds the day after a gymnastics test, I owe it to the horse to get him that fit, and this is one way I might approach that at home as a progression over the season. If I don’t have the horse peaking at that horse show, I do the same thing there because that’s part of his fitness plan.
Having said that, elite human athletes have off seasons so they don’t break in half, and I think @Foitin was implying that not everybody we are talking about is thinking that way. Top riders absolutely do. People chasing points in the Children’s Hunters? Not everyone is thinking about exercise physiology.