Alex knew he couldn't stop and he couldn't afford a moment of carelessness here.
By pushing everything in the front, he was setting an example for the soldiers of Kinley while on the other side, he was trying to evoke fear in the minds of the soldiers of Arkham.
He wants to break their minds due to a sense of hopelessness and fear while showing his domination and superiority as a warrior.
That's why even though he was surrounded, he didn't fall back or wait for his troops to catch on. He needs to make a path for his troops and make a path for them to follow.
And that wasn't the end of it, Alex's soldiers were also different from normal soldiers. They were also in a league of monsters of their own.
Even before a huge mass of enemies, they were utterly unfazed and following Alex's example, they showed the other side the true meaning of terror.
