Marcus clicked his teeth as he saw the walker move at the last minute preventing him from finishing it in one single hit. He briefly entertained the idea making another shot but with Albert being close enough, a shift of priorities is on his mind. After all the war is not won just by killing soldiers but also by taking land. In other words he will go for their material.

He would start for those that can fight back as it would make his allies' attack more easier. In fact his sensors are already locking on a vehicle that already landed a hit to Daedalus. 

Reload and Replace to Explosive Ammunition.

Aim and Lock on the Enemy Vehicle.

Then Pull the Trigger.