Alexander's Secret Weapon

The horses in a slow trot, almost menacingly made their way closer and closers, the sound of more than 8,000 beasts (2,000 from Ural, and 6,000 from Nibraz because each chariot was pulled by at least 2 horses, and sometimes even more) stamping their hooves against the ground making the very earth shake with trepidation.

Somehow the slow methodical approach was actually worse than a full gallop.

But why did horses not gallop this short distance?

Because if they had wanted to, they could have easily run this relatively short 1 kilometer.

Because there was a problem with that.

Simply, it was because it was far easier to maintain a solid line by controlling a horse's walking speed, rather than a running speed, similar to how humans can keep a solid line while walking, but it becomes very hard to do when they start running.

Because everyone walks around the same speed and its easier to synchronize with that, rather than a running speed, which is quite different for people.