Simultaneous Charge

Grahtos sped his 1,000 men as fast as he could toward the enemy.

And there were several reasons for doing this.

First and foremost was because he wanted to gain as much speed as he could before colliding with the enemy.

Another reason was that he did not want the horses any time to be afraid of the camel.

For the smell and size of this strange beast would make the steeds skittish and jumpy.

While the third reason was to cover the distance as fast as possible to get away from the javelin fire which would inevitably come.

And as soon as Grahtos entered the 50-meter range, Azab slowed down his speed and started launching a volley of javelin, followed by a second round, hoping to kill as many riders as possible riders and disrupt the formation.

The reason for doing so, as opposed to just simply charging head-on was because that was how the cavalry vs cavalry fight of the time would occur.