Think about it, the object is not to destroy but to control the menace and then control the flow of the fight. Now for a brief overview of Guerilla Warfare. Guerilla Warfare sets the rules of normal engaement on its head and it is this strangeness to it that often causes battles to be lost. It depends entirely upon being dynamic and maintaining momentum. I bet you never saw a WE general wait to absorb a charge.
Tactical evasion is as important as engaging the enemy when the time is right.
Standard military doctrine supports the concentration of forces providing both greater strength, and to the guerilla warrior an easy to reach target. Guerilla warfare demands that there be a multitude of targets, almost too many to know which target presents opportunity and which target presents a trap or waste of resources. Your troops should momentary coagulate into a coordinated strike and then scatter to the next mission. The key to being effective at or against guerilla warfare is knowing that its sucess depends on the ratio of space to force. The guerilla needs to spread out.