If you're outnumbered, you move and fight, but with greater numbers, you naturally think of ways to encircle the enemy and fight, taking full advantage of the numerical and firepower superiority.
Gao Yang and Andy He faced a rather unique situation, they had the overall advantage in numbers, but when they began flanking the enemy, they became two isolated forces in a position of weakness.
The Iron Madonna's fighters wouldn't just let themselves be slaughtered. Once they had a moment to respond, the situation could spiral out of control.
However, taking into consideration the element of surprise, Gao Yang and Andy He weren't in much danger. All they had to do was open fire quickly and kill all the enemies.