This statement doesn’t make sense to me. I’ve ridden (European-style) for a long time, I thought that walk, trot, canter and gallop were distinct due to the order a horse places its hooves during motion, hence why you change your seat/riding style for each transition.

Also, I’d not class walk and trot as different speeds (gallop, yes certainly the fastest). Obviously a trot is a more efficient way for a horse to move quicker but they can also trot very slowly (as often performed during dressage), slower than a fast walk, and similarly for a canter, much like we can jog very slowly.

Any other equestrians with a view on this? I’d be interested to hear if there’s anything I’m missing, I’ve never done any formal study all my knowledge is based on riding experience. Or is this a difference between western and European riding? I know the approaches are very different.